Q1:A large tank is filled with water. The pressure on the base of the fish tank is 4000N/m². The base of the tank is a rectangle measuring 2.0m by 4.5m. Calculate the force on the base caused by the base of the water.
Answer:
F = 36 kN
Explanation:
It is given that,
The pressure on the base of the fish tank is 4000N/m².
The base of the tank is a rectangle measuring 2.0m by 4.5m.
Area of the base of the tank is 9 m²
We need to find the force on the base caused by the base of the water. Pressure on the base of the tank is given by the force acting per unit area such that,
[tex]P=\dfrac{F}{A}\\\\F=P\times A\\\\F=4000\times 9\\\\F=36000\ N\\\\F=36\ kN[/tex]
So, the force of 36 kN is acting on the base by the base of water.
Resistance and resistivity are related by a: 1.factor that is dependent on the length of the material 2.factor that is dependent on the area of the material 3.proportionality constant dependent on the identity of the material 4.proportionality constant dependent on the source of the material
Answer:
1. factor that is dependent on the length of the material.
2. factor that is dependent on the area of the material
Explanation:
Resistance R is directly proportional to its length L of an object and it is inversely proportional to the crossectional area of that object.
Mathematically, this is represented as:
a) Resistance R is directly proportional to its length L of an object
R ∝ L ......... Equation 1
b) Resistance R is inversely proportional to the crossectional area (A) of an object
R ∝ 1/A ............ Equation 2
Combining the two equations together, we have:
Resistance R is directly proportional to its length L of an object
R ∝ L/A .......... Equation 3
Resistivity of a material is the natural or inherent or intrinsic property that a material has. The Resistivity of a material is not dependent on the length or crossectional area of such material. It is only temperature dependent.
The resistance of a material is also dependent on the resistivity of the material. This means the resistance of a material is directly proportional to the resistivity of the material.
R ∝ ρ........Equation 4
Combining Equation 4 and 3 together, we have:
R = ρL/A
Where:
R = Resistance
ρ = Resistivity
L = Length of the material
A = Crossectional area of the material
Resistance and resistivity are related by a factor that is dependent on the length of the material a factor that is dependent on the area of the material
A DC-9 aircraft leaves an airport from a runway whose bearing is N4343degrees°E. After flying for one half 1 2 mile, the pilot requests permission to turn 90degrees° and head toward the southeast. The permission is granted. After the airplane goes 1 mile in this direction, what bearing should the control tower use to locate the aircraft? What is the bearing that the control tower should use to locate the aircraft? ▼ S N nothingdegrees° ▼ E W (Round to the nearest tenth as needed.)
Answer:
103.4° or S76.6°E
Explanation:
The direction N43°E is perpendicular to the direction south-east when the plane turn 90° and heads in the south-east direction.
Since the distance 1/2 mile N43°E is perpendicular to the distance 1 mile south-east, we have a right angled triangle.
So, the angle θ between the aircraft's new position and old position is gotten from tanθ = 1 ÷ 1/2 = 2
θ = tan⁻¹(2) = 63.43°
So, the total angle from North to its new position is 40° + 63.43° = 103.43°
Since we need the south-east bearing, the angle from south is 180° - 103.43° = 76.57° ≅ 76.6°
So, our bearing is 103.4° or S76.6°E
Which graph shows the correct relationship between kinetic energy and speed?
Answer:
c. hope this helped
Explanation:
Evidence supports the idea that increases in carbon dioxide and methane in Earth's atmosphere are major contributors to global warming. This is based primarily on the fact that carbon dioxide and methane are excellent absorbers of Jun 12 #11 (1) gamma rays (3) visible light (2) microwaves (4) infrared radiation
Answer: 4. Infrared radiation
Explanation: Both carbon dioxide and methane are excellent absorbers of heat. The heat energy causes the molecule of carbon dioxide and methane to vibrate. As a result of this, the molecules gives up the extra energy by emitting infrared photon.
Therefore, the Evidence that supports the idea that increases in carbon dioxide and methane in Earth's atmosphere are major contributors to global warming is primarily based on the fact that carbon dioxide and methane are excellent absorbers of infrared radiation
A car runs 4200m on a straight path in 40 minute. find its velocity?
Answer:
velocity = displacement/time
= 4200m/ 2400s
= 1.75 m/s
Explanation:
40 minutes × 60 = 2400 seconds
A radioactive isotope has a half-life of 2 hours. If a sample of the element contains 600,000 radioactive nuclei at 12 noon, how many radioactive nuclei would be left at 6 pm?
Answer: There will be 75258 nuclei left at 6 pm.
Explanation:
a) half-life of the radioactive substance:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
[tex]t_{\frac{1}{2}}=\frac{0.69}{k}[/tex]
[tex]k=\frac{0.69}{t_{\frac{1}{2}}}=\frac{0.693}{2hours}=0.346hours^{-1}[/tex]
b) Expression for rate law for first order kinetics is given by:
[tex]A=A_0e^{-kt}[/tex]
where,
k = rate constant
t = time for decomposition = 6 hours ( from 12 noon to 6 pm)
A = activity at time t = ?
[tex]A_0[/tex] = initial activity = 600, 000
[tex]A=600000\times e^{-0.346\times 6}[/tex]
[tex]A=75258[/tex]
Thus there will be 75258 nuclei left at 6 pm.
I NEED. HELP PLEASE, THANKS! :) Air is an insulator. However, in winter you might experience a spark when your fingers touch a doorknob. Briefly explain why this happens.
Answer:
This is because of the static electricity which is generated in bodies due to friction. Time to time, the door knob gets touched by many people and the charge on it goes on increasing because of increasing friction. When the charge is increased much, after a considerable time, one may get a spark or a mild shock.
Which is an example of a fission reaction? Check all that apply.
H + H → He 2n
+
239 Pu + n + 1904 Ce + Kr + 2n
295 Am + in → 154 La + 95 Sr + 3 in
13C + H + 4N
Answer:
Check Explanation
The fission reactions include
239 Pu + n → Ce + Kr + 2n
And
295 Am + in → 154 La + 95 Sr + 3 n
Explanation:
A fission reaction is a radioactive reaction in which an atom with a heavy nuclei splits into atoms with smaller or lighter nuclei usually brought about by the attack of a fundamental particle and accompanied by the release of some fundamental particles (neutrons mostly) and energy.
Although, the reactions to be examined aren't totally clear, we can still guess which element is which and know which of the reactions has a heavier nuclei splitting into smaller ones.
1) H + H → He + 2n
Two hydrogen atoms combine to give an helium atom and release neutrons too, showing that here, smaller molecules combine to form a bigger one. Hence, this isn't a fission reaction, rather, it's a fusion reaction.
2) 239 Pu + n → Ce + Kr + 2n
Here, Pu (Plutonium, atomic mass 239), a heavy nuclei that splits into smaller nuclei, Ce (Cerium, atomic mass 140) and Kr (Krypton, atomic mass 84) together with some neutrons to fit the definition of a fission reaction. Hence, this reaction is a fission reaction.
3) 295 Am + n → 154 La + 95 Sr + 3 n
Here, Pu (Americium, atomic mass 295), a heavy nuclei that splits into smaller nuclei, Ce (Lamthanium, atomic mass 154) and Sr (Strontium, atomic mass 95) together with some neutrons to fit the definition of a fission reaction. Hence, this reaction is a fission reaction.
4) 13C + H → 14N
Carbon 13 combines with a hydrogen element to mutate and give nitrogen-14, a heavier nuclei, showing all signs of a nuclear fission and not fission.
Hope this Helps!!!
Answer:
b and c
Explanation:
got it correct on edg
A heart beats 10 times in 10 seconds.
How many times does it beat in 1 minute?
Answer:
60
Explanation:
60secs = 1 minute
if you want to show you work further then
10 divided by 10 = 1
so each second is 1 heart beat
so then just 60 divided by 10 equals 6
so then just do 6 times 10 equals 60 beats
A boy rides motorbike with velocity of 20 m/s He accelerates his motorbike
to a velocity of 30 m/s for 5 second. Calculate the acceleration produced in the
motorbike.
[Ams 2ms
Answer:
2m/s^2
Explanation:
Initial velocity(u) = 20m/s
Final velocity(v) = 30m/s
Time(t) = 5s
Using Acceleration(a) = change in velocity/time
a = v-u/t
a = 30-20/5
a = 10ms/5s
a = 2m/s^2
A boy of mass 45kg sits 109cm to the left of the seesaw. Another boy of mass 29000g wants to balance the seesaw. At what distance he needs to sit?
Answer:
166 cm
Explanation:
Given :
d1 =109cm
M1= 45kg
M2=29000g = 29 kg
As we know that Newton second law
[tex]Force\ =\ Mass\ *\ Acceleration[/tex]
Here M1= 45kg
and acceleration=[tex]9.81 m/s^{2}[/tex]
Therefore
[tex]F1=45 * 9.81[/tex]
[tex]F1= 441.45 N[/tex]
M2=29000g = 29 kg
Similarly
[tex]F2= 29 * 9.81\\ F2= 284.4 N[/tex]
Now we using the Principal of moments
[tex]F1 * d1 =F2 *d2[/tex]
[tex]441.5 * 109\ =\ 290\ *\ d2\\48,123.5=290 d2\\d2 =165.9[/tex]
~ d2=166 cm
I NEED HELP PLEASE, THANKS! :)
Tom’s father is 48 years old. He is not able to see nearby objects clearly.
-What may be the reason for his vision problem?
-Where are images formed in this type of defected vision?
-How is this defect corrected?
Answer:
Explanation:
1) Hypermetropia (better known as Farsighted- this is why nearby objects seem blurry for him)
2) In such instances, image are typically formed farther from the near point
3) Such defects are quite common so there are common procedures such as using convex lens which can restore the sight to normal.
Magnesium metal reacts with hydrochloric acid to form magnesium chloride and hydrogen gas. Suppose we react an excess of magnesium metal with 20.0 mL of a 3.00 M solution of hydrochloric acid and collect all of the hydrogen in a balloon at 25°C and 1.00 atm. What is the expected volume of the balloon?
Answer:
0.734 L or 734 mL
Explanation:
We'll begin by calculating the number of mole of HCl in 20.0 mL of a 3.00 M solution of hydrochloric acid, HCl.
This is illustrated below:
Molarity of hcl = 3 M
Volume = 20 mL = 20/1000 = 0.02 L
Mole of HCl =..?
Molarity = mole /Volume
3 = mole /0.02
Cross multiply
Mole of HCl = 3 x 0.02
Mole of HCl = 0.06 mole.
Next, we shall determine the number of mole of Hydrogen gas, H2 produced from the reaction of 0.06 mole of HCl. This can obtain as follow:
Mg + 2HCl —> MgCl2 + H2
From the balanced equation above,
2 moles of HCl reacted to produce 1 mole H2.
Therefore, 0.06 mole of HCl will react to produce = (0.06 x 1)/2 = 0.03 mole
Therefore, 0.03 mole of H2 was produced.
Finally, we shall determine the volume of the balloon by calculating the volume of Hydrogen gas, H2 in the balloon.
The volume of H2 can be obtained by using the ideal gas equation as follow:
Pressure (P) = 1 atm
Temperature (T) = 25°C = 25°C + 273 = 298K
Number of mole (n) of H2 = 0.03 mole
Gas constant (R) = 0.0821 atm.L/Kmol
Volume (V) of H2 =?
PV = nRT
1 x V = 0.03 x 0.0821 x 298
V = 0.734 L = 734 mL.
Therefore, the volume of the balloon is 0.734 L or 734 mL
Question 13 of 32
1 Point
For a satellite to orbit Earth at a constant distance, its centrifugal acceleration
must be equal and opposite Earth's gravitational acceleration. If a satellite is
to orbit at a constant distance from Earth at a circular radius of 7,000,000 m,
what is the required velocity of the satellite? (Assume the acceleration due to
Earth's gravity is 8.2 m/s2 at this altitude.)
O A. 8239 m/s
O B. 7576 m/s
C. 6818 m/s
D. 7043 m/s
Answer: B
V = 7576 m/s
Explanation: Given that the
circular radius R = 7,000,000 m,
The acceleration due to Earth's gravity is 8.2 m/s2
Let's use gravitational field strength formula to get the mass of the satellite.
g = Gm/R^2
Where G = 6.674×10^−11m3⋅kg−1⋅s−2
Substitutes all the parameters into the formula
8.2 = (6.674×10^-11 × M)/(7000000)^2
Cross multiply
4.018 × 10^14 = 6.674×10^−11M
Make M the subject of formula
M = 4.018 × 10^14 ÷ 6.674×10^−11
M = 6.02 × 10^24 kg
The Force of attraction experienced by the satellite will be
F = mg
F = 6.02 × 10^24 × 8.2
F = 4.94 × 10^25 N
But centripetal force is
F = MV^2/ R
Where V = velocity of the satellite
Substitute F, M and R into the formula
4.94×10^25 = (6.02×10^24V^2)/ 7 ×10^6
Cross multiply
3.46 × 10^32 = 6.02×10^24V^2
Make V^2 the subject of formula
V^2 = 3.46×10^32 ÷ 6.02×10^24
V^2 = 57403600.2
Find the square root of the value to get V
V = 7576 m/s
The required velocity of the satellite is 7576 m/s approximately
how can you tell the stigma from the stamens in the flowers
Answer:
for wind pollinated flowers they have long feathery stigma that hangs outside the flower while insect pollinated have short stigma that is shorter than even the petals and it's inside the flower
Also thestigma has something that looks like a bulb underneath it and that is the ovary while the stamen is just straight
When the current in a coil flows in anti-clockwise direction, what pole does it create?
Answer:
The North Pole.
Explanation:
According to the Lenz's law of electromagnetic induction, an induced elemagnetic force tends to give rise to the current. In reaction, this current's magnetic field try to oppose any replacement in the magnetic flux.
So, as per the law of Lenz's electromagnetic induction, when the current passes in a coil in anti-clockwise direction, this will produce the opposite end of the coil in the north pole.
So, the correct answer is north pole.
If you only 24 hours too live, how would you spend it...
Answer:
I would spend the 24 hours with joy and fun ...
Like I would go for a walk of 30 minutes with my puppy . And than I will spend my 2 hours with my friends on going to shopping . And than 2 hrs just helping the poors .And than just gonna waste my 30 minutes with my younger sister . And than 2 hrs with my my grandpa and with my grandmom . And than just going to the cinema to watch a movie with my parents for 3 hrs and than just . Amd than just going to have a good sleep for 14 hrs .
Explanation:
Hope it works out !!!
A moving particle encounters an external electric field that decreases its kinetic energy from 9970 eV to 6340 eV as the particle moves from position A to position B The electric potential at A is 55.0 V and that at B is 19.0 V Determine the charge of the particle Include the algebraic sign or with your answer
Answer:
q = -1.61x10⁻¹⁷ C
Explanation:
The charge of the particle can be found using the definition of the work done by electric force:
[tex] W = -q\Delta V [/tex] (1)
Where:
q: is the charge
ΔV: is the difference in electric potential
The work is also equal to:
[tex] W = E_{p_{A}} - E_{p_{B}} [/tex] (2)
Where:
[tex]E_{p_{A}}[/tex] and [tex]E_{p_{B}}[/tex] are the electric potential energy of the points A and B, respectively.
Now, by conservation of energy we have:
[tex] K_{A} + E_{p_{A}} = K_{B} + E_{p_{B}} [/tex] (3)
Where:
[tex]K_{A}[/tex] and [tex]K_{B}[/tex] are the kinetic energy of the points A and B, respectively.
Rearranging equation (3):
[tex] K_{B} - K_{A} = E_{p_{A}} - E_{p_{B}} [/tex]
[tex] K_{B} - K_{A} = W [/tex]
[tex] K_{B} - K_{A} = -q\Delta V [/tex]
Solving the above equation for q:
[tex] q = -\frac{K_{B} - K_{A}}{V_{B} - V_{A}} = -\frac{6340 eV - 9970 eV}{19.0 V - 55.0 V} = -100.83 e \cdot \frac{1.6 \cdot 10^{-19} C}{1 e} = -1.61 \cdot 10^{-17} C [/tex]
Therefore, the charge of the particle is -1.61x10⁻¹⁷ C.
I hope it helps you!
To which category does galaxy #1 belong? Why does it belong in this category?
Answer:
This galaxy belongs to the elliptical galaxy category. This is because it does not have spiral arms.
I NEED HELP PLEASE, THANKS! Describe each Newton Law. :)
Explanation:
Newton's first law: Inertia
"An object in motion stays in motion, and an object at rest stays at rest, until acted upon by an unbalanced force."
This means that an object does not speed up, slow down, or change direction, unless the forces acting on it are unbalanced.
Newton's second law: Net force
∑F = ma
The net force (the sum of the forces acting on an object) is equal to the object's mass times its acceleration.
Newton's third law: Action/reaction
"For every action, there is an opposite and equal reaction."
This means that when one object pushes on another object (action), the second object pushes back with an equal and opposite force (reaction).
Calculate the force exerted by a machine that does 4800 J of work over a distance of 22.5 m?
Answer:
About 213.33 N
Explanation:
Force can be found using the following formula:
F= w/d
where w is work in Joules (J) and d is distance in meters (m).
We know that the machine does 4800 Joules of work over a distance of 22.5 meters. Therefore,
w=4800 J
d=22.5 m
Substitute these values into the formula.
F= 4800 J/ 22.5 m
Divide 4800 by 22.5
F= 213.333333 J/m
Let's round to the nearest hundredth. The 3 in the thousandth place indicates the 3 in the hundredth place should stay.
F= 213.33 J/m
1 J/m is equal to 1 Newton, or N.
F= 213.33 N
The force exerted by the machine is about 213.33 Newtons
A uniform metal tube of length 5m and mass 9kg is suspended by two vertical wires attached at 50cm and 150cm respectively from the ends of the tube. Find the tension in each wire
Answer:
force (tension) of 29.4 N (upward) in 100 cm
force (tension) of 58.4 N (upward) in 200 cm
Explanation:
Given:
Length of tube = 5 m (500 cm)
Mass of tube = 9
Suspended vertically from 150 cm and 50 cm.
Computation:
Force = Mass × gravity acceleration.
Force = 9.8 x 9
Force = 88.2 N
So,
Upward forces = Downward forces
D1 = 150 - 50 = 100 cm
D2 = 150 + 50 = 200 cm
And F1 = F2
F1 x D1 = F2 x D2
F1 x 100 = F2 x 200
F = 2F
Total force = Upward forces + Downward forces
3F = 88.2
F = 29.4 and 2F = 58.8 N
force (tension) of 29.4 N (upward) in 100 cm
force (tension) of 58.4 N (upward) in 200 cm
The fielder attempts to catch a second ball. Just before the fielder catches the ball, the air resistance acting on the ball is 1.2N. Calculate the resultant force acting on the ball. Remember to include its direction and the unit. Assume the ball is falling vertically
Answer:
Resultant force = (1.2 - 9.8m)ĵ N
where m = mass of the ball
Magnitude of the resultant force = (9.8m - 1.2) N
Since the weight of the ball is expected to exceed the air resistance (because the ball is falling vertically downwards), the direction of the resultant force is vertically downwards. Its unit is Newtons, the SI unit of Force.
Explanation:
If a ball is falling vertically downwards, the only two forces acting on the ball include the weight of the ball (the pull of gravity on the ball) and the air resistance on the ball.
Weight of the ball acts downwards and is given as mg. where m = mass of the ball and g is the acceleration due to gravity = 9.8 m/s²
W = mg = (9.8m) N
In vector form, W = (-9.8mĵ) N
The air resistance on the ball = 1.2 N, the air resistance acts in the direction opposite the motion of the ball, and since the ball is moving vertically downwards, the air resistance acts vertically upwards.
In vector form, the air resistance = (1.2ĵ) N
Hence, the resultant force acting on the ball is the vector sum of all the forces acting on the ball.
Resultant force = (-9.8mĵ) + (1.2ĵ)
= (1.2 - 9.8m)ĵ N
Since the weight of the ball is expected to exceed the air resistance (because the ball is falling vertically downwards), the direction of the resultant force is vertically downwards.
Hope this Helps!!!
Which refers to a measure of how acidic or basic a solution is? a]pH b]solubility c]reactiveness d]hardness
Answer:
Option(a) i.e" pH" is the correct answer to the given question .
Explanation:
The main objective of pH value is to determining whether the solution is the acidic or the basic solution.The pH is determining the solution whether it is basic or acidic with the help of there pH value .The range of the pH value is from 0 to 14 with the following parameter it determines whether the solution is basic ,acidic or the neutral solution .
If pH value is 7 then it is neutral solution .If pH value is greater then 7 then the solution is then it is basic solution .If the pH value is less then 7 then the solution is the Acidic solution .All the other option are not determining that whether the solution is acidic or the basic solution that's why these are incorrect option .
Answer:
the answer is A pH
got it right 2020
Explanation:
Earth's atmosphere is made up of mostly nitrogen (78%) and oxygen (21%); however, there are other gases in smaller amounts, like argon, carbon dioxide, neon, helium, hydrogen, and more. If there was an increase of carbon dioxide in the atmosphere, how would this affect temperature? A) The temperature would increase globally. B) The temperature would decrease globally. C) Temperature doesn't relate to the composition of the atmosphere; it has to do with the sun's rays. D) The temperature would not be affected since carbon dioxide is only one component in the atmosphere.
Answer:
the temperature would increase globally because carbon dioxde contributes to global warming increase the temperature of the earth
Explanation:
i hope this will help you
If there is an increase of carbon dioxide in the atmosphere, this affects temperature the temperature would increase globally. The correct option is B.
What is global warming?The term “global warming” refers to a steady increase in the average temperature of the Earth's atmosphere and oceans, a phenomenon that is thought to be irreversibly altering the Earth's climate.
Our poles' waters are melting as a result of global warming. When our polar ice caps melt the majority of the way, many coastal communities will flood. Extreme weather, such as greater hurricanes, larger thunderstorms, and wider areas affected by other natural catastrophes, will also occur.
The temperature would decrease globally because carbon dioxide contributes to global warming, increasing the temperature of the earth.
Therefore, the correct option is B) The temperature would decrease globally.
To learn more about global warming, refer to the link:
https://brainly.com/question/7486747
#SPJ2
A wooden block of 0.60 kg is placed on a rough surface where it is accelerated at the rate of 4 m/s2. If the force applied on the block is 12N,what frictionless force is affecting the motion of block?
Answer:
Take a look below
Explanation:
A stone is dropped from a tower of height 3600cm.Find the velocity by which it strike the ground.Find the time taken to reach the ground.
Answer:
1. 26.56m/s.
2. 2.71 secs.
Explanation:
The following data were obtained from the question:
Height (h) = 3600cm
Velocity (v) =..?
Time (t) =..?
Next, we shall convert the height, 36000cm to metre (m). This is illustrated below:
100cm = 1m
Therefore, 3600cm = 3600/100 = 36 m
Therefore, the height is 36m.
1. Determination of the velocity with which the stone struck the ground. This is illustrated below:
Acceleration due to gravity (g) = 9.8m/s²
Height (h) = 36m
Velocity (v) =.?
v² = 2gh
v² = 2 x 9.8 x 36
v² = 705.6
Take the square root of both side.
v = √705.6
v = 26.56m/s
Therefore, the velocity with which the stone struck the ground is 26.56m/s.
2. Determination of the time taken for the stone to reach the ground.
Height (h) = 36m
Acceleration due to gravity (g) = 9.8m/s²
Time (t) =.?
t = √(2h/g)
t = √(2 x 36/ 9.8)
t = √(72/9.8)
t = 2.71 secs
Therefore, the time taken for the stone to reach the ground is 2.71 secs
A ball is falling at terminal velocity. Terminal velocity occurs when the ball is in equilibrium and the forces are balanced. Which free body diagram shows the ball falling at terminal velocity? A free body diagram with one force pointing downward labeled F Subscript g Baseline 20 N. A free body diagram with 2 forces: the first pointing downward labeled F Subscript g Baseline 20 N and the second pointing upward labeled F Subscript air Baseline 20 N. A free body diagram with 2 forces. The first pointing downward labeled F Subscript g Baseline 20 N and the second pointing upward labeled F Subscript air Baseline 5 N. A free body diagram with 2 forces: the first pointing downward labeled F Subscript g Baseline 20 N and the second pointing upward labeled F Subscript air Baseline 30 N.
Answer:
A free body diagram with 2 forces: the first pointing downward labeled F Subscript g Baseline 20 N and the second pointing upward labeled F Subscript air Baseline 20 N.
Explanation:
This is because at terminal velocity, the ball stops accelerating and the net force on the ball is zero. For the net force to be zero, equal and opposite forces must act on the ball, so that their resultant force is zero. That is F₁ + F₂ = 0 ⇒ F₁ = -F₂
Since F₁ = 20 N, then F₂ = -F₁ = -20 N
So, if F₁ points upwards since it is positive, then F₂ points downwards since it is negative.
So, a free body diagram with 2 forces: the first pointing downward labeled F Subscript g Baseline 20 N and the second pointing upward labeled F Subscript air Baseline 20 N best describes the ball falling at terminal velocity.
Answer:
b
Explanation:
An energy input of 33.44kJ is required to raise the temperature of 100 grams of water from room temperature (20°C) to boiling temperature (100°C). How many photons of energy are needed to bring 250 grams of room temperature water to boiling if 288 mili-meter electro-magnetic radiation is used to heat the water?
Answer:
1.21 × 10²⁵ photons
Explanation:
If 33.44kJ is required to raise the temperature of 100 grams of water from room temperature (20°C) to boiling temperature (100°C), then the quantity of heat Q 33.44kJ is required to raise the temperature of 250 grams of water from room temperature (20°C) to boiling temperature (100°C) is
Q/33.44 kJ = 250 g/100g
Q = 2.5 × 33.44 kJ = 83.6 kJ
Now the energy of a photon of 288 millimeter electromagnetic radiation is
E = hc/λ where h = planck's constant = 6.63 × 10⁻³⁴ Js, c = speed of light = 3 × 10⁸ m/s and = 288 × 10⁺³ m = 2.88 × 10⁻⁵ m
E = 6.63 × 10⁻³⁴ Js × 3 × 10⁸ m/s ÷ 2.88 × 10⁻⁵ m
= 19.89/2,88 × 10⁻²¹ J
= 6.91 × 10⁻²¹ J
The number of photons of the 288 mm radiation that will raise 250 grams of water from room temperature to boiling point is thus,
n = Q/E = 83.6 kJ/6.91 × 10⁻²¹ J
= 83.6 × 10³ J/6.91 × 10⁻²¹ J
= 12.1 × 10²⁴ photons
= 1.21 × 10²⁵ photons
