Answer:
t = 16.5 s
Explanation:
First we apply first equation of motion to the accelerated motion of the rocket:
[tex]v_{f1} = v_{i1} + at_{1}[/tex]
where,
vf₁ = final speed of rocket during accelerated motion = ?
vi₁ = initial speed of rocket during accelerated motion = 0 m/s
a = acceleration of rocket during accelerated motion = 30 m/s²
t₁ = time taken during accelerated motion = 4 s
Therefore,
[tex]v_{f} = 0\ m/s + (30\ m/s^2)(4\ s)\\\\v_{f} = 120\ m/s[/tex]
Now, we analyze the motion rocket when engine turns off. So, the rocket is now in free fall motion. Applying 1st equation of motion:
[tex]v_{f2} = v_{i2} + g t_{2}[/tex]
where,
vf₂ = final speed of rocket after engine is off = 0 m/s
vi₂ = initial speed of rocket after engine is off = Vf₁ = 120 m/s
g = acceleration of rocket after engine is off = - 9.8 m/s² (negative sign for upward motion)
t₂ = time taken after engine is off = ?
Therefore,
[tex]0\ m/s = 120\ m/s + (- 9.8\ m/s^2)(t_{2})\\\\t_{2} = \frac{120\ m/s}{9.8\ m/s^2}\\\\t_{2} = 12.25\ s[/tex]
So, the time taken from the firing position till the stopping position is:
[tex]t = t_{1} + t_{2}\\\\t = 4 s + 12.5 s[/tex]
t = 16.5 s
I WILL GIVE YOU BRAINLIEST!!
Which physical quantity does not change when a piece of copper is heated?
Answer:
Resistance, resistivity and drift velocity varies with relaxation time which is dependent on temperature.
Number of free electrons in a conductor remains invariant even if its temperature changes.Hence correct option is option D.
Radioisotopes often emit one or more types of radiation, including alpha particles, beta particles, and gamma rays. The distance the radiation travels through matter before being absorbed increases in order from alpha to gamma. Which statement describes the best radioisotope that can be used for radioisotope imaging and for radionuclide therapy?
It emits only gamma rays.
It emits only alpha particles.
It emits alpha and beta particles.
It emits beta particles and gamma rays.
Answer:
The most correct option is the last option
Explanation:
During radioisotope/nuclear imaging in diagnosis, the radioisotope must emit gamma rays from within the body. However, in the case of radionuclide therapy, most radionuclides emit beta particles while some others also emit gamma rays.
Answer:
D
Explanation:
True of False, in physics the term weight and force of gravity have the
same meaning?"
Help with both questions please.
Answer:
1) True
2) None of the above
Explanation:
Q # 1:
Weight is actually the gravitational force or force of gravity. So, it's true.
Q # 2:
None of above because force of gravity can not be negative. In order to have a negative weight, the body has to be "repelled" by gravity.
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!
~AH1807A child's first bicycle has 12-inch tires. These tires have a 6-inch radius. How fa r does the bicycle move forward each time the wheel makes one complete rotation? Give your answer in meters. (1 inch = 0.022 meters) b. A woman's ten-speed bicycle has 27-inch tires (13.5-inch radius). How far does this bicycle …
Answer:
a. s = 0.96 m
b. s = 2.15 m
Explanation:
a.
The relationship between the linear displacement and the angular displacement is given as follows:
[tex]s = r\theta[/tex]
where,
s = linear distance covered = ?
r = radius of wheel = (6 in)(0.0254 m/1 in) = 0.1524 m
θ = angular displacement = (1 rev)(2π rad/1 rev) = 2π rad
Therefore,
[tex]s = (0.1524\ m) 2\pi[/tex]
s = 0.96 m
b.
Assuming, we have to find linear displacement here, as well:
[tex]s = r\theta[/tex]
where,
s = linear distance covered = ?
r = radius of wheel = (13.5 in)(0.0254 m/1 in) = 0.3429 m
θ = angular displacement = (1 rev)(2π rad/1 rev) = 2π rad
Therefore,
[tex]s = (0.3429 \ m) 2\pi[/tex]
s = 2.15 m
a crowbar 2 metres long is used to lift a rock weighing 800 newtons .If the fulcrum is 0.25 metre,from where the bar touches the rock, how much effort must be applied to move the rock
Answer:
??
Explanation:
HELP ASAP!! WILL TRY TO GIVE BRAINLIEST
How are ribosomes different from other complex animal cell organelles?
Explanation:
Ribosomes are not quite the same as different organelles since they have no layer around them that isolates them from different organelles, they comprise of two subunits, and when they are creating sure proteins they can become film bound to the endoplasmic reticulum, however they can likewise be free drifting while at the same time performing
How does an increase in thermal energy affect the temperature of each state of matter?
Answer:
Explanation:
When thermal energy is added to a substance, its temperature increases, which can change its state from solid to liquid (melting), liquid to gas (vaporization), or solid to gas (sublimation). ... When the pressure exerted on a substance increases, it can cause the substance to condense.
Answer:
Gases have the highest kinetic energy of any state of matter and thus occur at the highest temperatures. Increasing the temperature of a gas in an open system will not further change the state of matter because the gas molecules will only become infinitely further apart.
what is this Regeneration
Answer:
Regeneration means that an organism regrows a lost part, so that the original function is restored.
Find the force of gravity acting between at 1.7x10^30 kg planet with
5.5x10^20 kg moon that is 2x10^5 m away.
A) 4.0x10^30 N
B) 5.0x10^30 N
C) 4.3x10^30 N
D) 9.8x10^30 N
None of these answers are correct...
Applying the law of universal gravitation, we have
F = G m₁ m₂ / R²
where
G = 6.67 × 10⁻¹¹ N•m²/kg²
m₁ = 1.7 × 10³⁰ kg
m₂ = 5.5 × 10²⁰ kg
R = 2 × 10⁵ m
→ F = (6.67 × 1.7 × 5.5)/2² × 10⁻¹¹⁺³⁰⁺²⁰⁻¹⁰ N
→ F ≈ 15.59 × 10²⁹ N
→ F ≈ 1.6 × 10³⁰ N
A car was moving a 14 m/s. After 30 seconds, it’s speed increased to 20 m/s. What was its acceleration during this time?
Answer:
acceleration = 0.2 m/s/s
Explanation:
initial velocity u = 14
final velocity v = 20
time = 30
acceleration = ?
v = u + at
20 = 14 + 30a
30a = 6
a = 0.2 m/s/s
Answer:
For the aceleration we have:
V = Vi + a * t
Being:
V = 20 m/s
Vi = 14 m/s
a = ?
t = 30 s
Then, lets replace acording the formula:
20 m/s = 14 m/s + a * 30 s
Clear "a":
a = (20 m/s - 14 m/s) / 30 s
a = (6 m/s) / 30 s
a = 0,2 m/s²
The aceleration of the car is 0,2 meters per second squared.
help please 10 pts and quick!
Answer:
A
Explanation:
A 0.05 kg ball is attached to the end of a 0.5 m long string. The ball is spun around a circle with a period of 0.20 s. What is the tension force in the string?
The ball spins once around the circle in 0.20 s, meaning it travels a distance equal to its circumference in that time, giving it a linear speed of
v = (2π (0.5 m)) / (0.20 s) = 5π m/s ≈ 15.708 m/s
Use this compute the magnitude of the centripetal acceleration a :
a = v²/ (0.5 m) = 50π² m/s² ≈ 493.48 m/s²
Use Newton's second law to compute the mangitude of the tension F in the string:
F = (0.05 kg) a = 5/2 π² N ≈ 24.674 N ≈ 25 N
An airplane flies at 40 m/s at an altitude of 50 meters. The pilot drops a heavy package which falls to the ground. Where, approximately, does the package land relative to the plane's new position
Answer:
128 m
Explanation:
From the question given above, the following data were obtained:
Horizontal velocity (u) = 40 m/s
Height (h) = 50 m
Acceleration due to gravity (g) = 9.8 m/s²
Horizontal distance (s) =?
Next, we shall determine the time taken for the package to get to the ground.
This can be obtained as follow:
Height (h) = 50 m
Acceleration due to gravity (g) = 9.8 m/s²
Time (t) =?
h = ½gt²
50 = ½ × 9.8 × t²
50 = 4.9 × t²
Divide both side by 4.9
t² = 50 / 4.9
t² = 10.2
Take the square root of both side
t = √10.2
t = 3.2 s
Finally, we shall determine where the package lands by calculating the horizontal distance travelled by the package after being dropped from the plane. This can be obtained as follow:
Horizontal velocity (u) = 40 m/s
Time (t) = 3.2 s
Horizontal distance (s) =?
s = ut
s = 40 × 3.2
s = 128 m
Therefore, the package will land at 128 m relative to the plane
Name all of the steps on the Physical Activity Pyramid?
Answer:
The steps are:-
Moderate physical activityVigorous aerobicsVigorous sport and recreationMuscle fitness exerciseFlexibility exerciseAvoiding inactivityBalancing energyThe pitch of a sound is most closely related to what ?
b. The coefficient of friction between the tires and the road is 0.850 and the mass of the car is
1.35x10' kg. Draw the free body diagram of this situation and determine the applied force
that caused the acceleration from part a. (2 law: Fnet-ma)
Given:
u
בנו
Samt
g=9.8 m/s^2
am
(from part a)
Unknown:
Fapp = ?
Equation:
Fnet=ma
Fapp- umg=ma
Solution:
Answer:
156.26N
Explanation:
The data needed are incomplete. Let the acceleration of the body be 3.5m/s²
Other given parameters
Mass = 1.35×10^1 = 13.5kg
coefficient of friction between the tires and the road = 0.850
Acceleration due to gravity = 9.8m/s²
According to Newton's second law:
Fnet = ma
Fnet = Fapp - Ff
Fapp is the applied force
Ff is the frictional force = umg
The equation becomes:
Fapp - Ff = ma
Fapp-umg = ma
Fapp - 0.85(13.5)(9.8) = 13.5(3.5)
Fapp - 109.0125 = 47.25
Fapp = 47.25+109.0125
Fapp = 156.2625N
Hence the applied force that caused the acceleration is 156.26N
Note that the acceleration of the car was assumed. Any value of acceleration can be used for the calculation.
A ray of light incident in water strikes the surface separating water from air making an angle of 10 ° with the normal to the surface. (refractive index of water = 1.3) a) What is the angle of refraction? b) What should be the angle of incidence if we want an angle of refraction not greater than 45 ° ? c) What is the critical angle?
Answer:
a
[tex]\theta _2 = 13^o[/tex]
b
[tex]\theta _1 =32.94^o[/tex]
c
[tex]\theta_c = 53.05^o[/tex]
Explanation:
From the question we are told that
The angle of incidence is [tex]\theta_1 = 10^o[/tex]
The refractive index of water is [tex]n_1 = 1.3[/tex]
Generally Snell's law is mathematically represented as
[tex]n_1 sin(\theta_1) = n_2 sin(\theta_ 2)[/tex]
Here [tex]n_2[/tex] is the refractive index of air with value [tex]n_2 = 1[/tex]
[tex]\theta_2[/tex] is the angle of refraction
So
[tex]\theta _2 = sin^{-1}[\frac{n_1 * sin(\theta _1)}{n_2} ][/tex]
=> [tex]\theta _2 = sin^{-1}[\frac{1.3 * sin(10)}{1} ][/tex]
=> [tex]\theta _2 = 13^o[/tex]
Given that the angle should not be greater than [tex]\theta _2 =45^o[/tex] then the angle of incidence will be
[tex]\theta _1 = sin^{-1}[\frac{n_2 * sin(\theta _2)}{n_1} ][/tex]
=> [tex]\theta _1 = sin^{-1}[\frac{1 * sin(45)}{1.3} ][/tex]
=> [tex]\theta _1 =32.94^o[/tex]
Generally for critical angle is mathematically represented as
[tex]\theta_c = sin^{-1}[\frac{n_2}{n_1} ][/tex]
=> [tex]\theta_c = sin^{-1}[\frac{1}{1.3} ][/tex]
=> [tex]\theta_c = 53.05^o[/tex]
two Force one of 12 Newton and another 24 Newton acts at 90 degree with each other find the resultant of two force and its direction
Answer:
Fr = 26.83 [N]
Explanation:
To solve this problem we must use the Pythagorean theorem, since the forces are vector quantities, that is, they have magnitude and density. Therefore the Pythagorean theorem is suitable for the solution of this problem.
[tex]F_{r}=\sqrt{(12)^{2}+(24)^{2} } \\F_{r}=26.83[N][/tex]
WHICH ONE IS IT????
RINGS
POINT
GRAPH
READS
TALKS
Answer: c or b
Explanation:
A 10 Kg dog is running with a speed of 5.0 m/s what is the minimum work required to stop the dog
Answer:
25J
Explanation:
Given parameters:
Mass of the dog = 10kg
Speed of the dog = 5m/s
Unknown:
The minimum energy required to stop the dog = ?
Solution:
The dog is moving with a kinetic energy and to stop the dog, an equal amount of kinetic energy generated must be applied to the dog.
To find the kinetic energy;
K.E = [tex]\frac{1}{2}[/tex] m v²
m is the mass
v is the velocity
Now insert the parameters and solve;
K.E = [tex]\frac{1}{2}[/tex] x 10 x 5 = 25J
A sea turtle must crawl up a beach to lay eggs. Ignoring friction, what work must a 140-kg turtle do in lifting herself 2.5 m above the level of the sea?
Answer:
3500joules of work
Explanation:
Work done = Force×,distance
Given
Focrce= mass ,× acceleration = 140×10 = 1400N
Distance moved = 2.5m
Workdone = 1400×2.5
Work done = 140×25
Workdone = 3500Joules
Write true if the statement is correct and false if the statement
1. Magnetic poles always appear in pair.
2. Iron and nickel are examples of magnetic materials.
3. The two ends of a magnet are called magnetic poles.
4. Two similar magnetic poles attract each other
5. If one end of an iron bar attracts one pole of a com
Grade 7 Physics
then the iron bar must be a magnet.
Match the terms in column A with the phrases in colu
B
Answer:
true false
Explanation:
Answer:
1.true
2.true
3.true 4.false 5.true
Choose the sequence of energy forms that best fits each item.
Answer:
1. chemical energy --> electrical energy --> light energy
2. Electrical Energy --> Mechanical Energy
3. Electrical Energy --> Heat Energy
4. Chemical Energy --> Thermal Energy --> Mechanical Energy
5. Nuclear Energy --> Light energy and thermal energy
6. Mechanical Energy --> Electric Energy
7. Chemical Energy --> Electrical Energy --> Sound Energy
8. Mechanical Energy --> Sound Energy
Explanation:
1.FLASHLIGHT:
chemical energy --> electrical energy --> light energy
The chemical energy from the cell batteries is converted to electrical energy, which is used to produce the light energy in form of flashlight.
2.ELECTRIC SAW:
Electrical Energy --> Mechanical Energy
The electrical energy from the socket is converted to the mechanical energy used to run the saw blade.
3.TOASTER:
Electrical Energy --> Heat Energy
The electrical energy from the socket is converted to the heat energy (thermal energy) used in browning the bread.
4.GAS POWERED SCOOTER:
Chemical Energy --> Thermal Energy --> Mechanical Energy
The chemical energy from fuel, such as petrol is converted to heat (thermal energy) in the engine by the process of combustion. This heat is then used to do work by conversion into mechanical energy, through piston movement, which in turn moves the shaft and the scooter.
5.THE SUN:
Nuclear Energy --> Light energy and thermal energy
The nuclear reactions on Sun provide nuclear energy which is converted into light and thermal energy that reaches us on earth.
6.WIND TURBINE:
Mechanical Energy --> Electric Energy
The mechanical energy is provided by wind when it rotates the blade of turbine. This is then converted to electrical energy b the turbine.
7.IPOD:
Chemical Energy --> Electrical Energy --> Sound Energy
The chemical energy i supplied by the battery of ipod, which is converted to electrical energy and that electrical energy is used to produce sound by ipod.
8.SPEAKER VIBRATES
Mechanical Energy --> Sound Energy
The mechanical energy due to vibration produces sound energy.
Answer:
1. chemical energy --> electrical energy --> light energy
2. Electrical Energy --> Mechanical Energy
3. Electrical Energy --> Heat Energy
4. Chemical Energy --> Thermal Energy --> Mechanical Energy
5. Nuclear Energy --> Light energy and thermal energy
6. Mechanical Energy --> Electric Energy
7. Chemical Energy --> Electrical Energy --> Sound Energy
8. Mechanical Energy --> Sound Energy
Explanation:
Why is it difficult to use the law of conservation of energy to calculate the
effects of a collision?
Answer:
B
Explanation:
In a collision some of the kinetic energy of the object convert into thermal energy and sound. It's not so easy to measure thermal and sound energy. That's why it's difficult to use law of conservation of energy.
Alert: Energy is always conserved.
what other factor affected the gravitational force between the two objects in this simulation?
Answer:
The strength of the gravitational force between two objects depends on two factors, mass and distance. the force of gravity the masses exert on each other. If one of the masses is doubled, the force of gravity between the objects is doubled. increases, the force of gravity decreases
A thermal cap used in certain apparatus consist of silica rod which fits tightly inside an aluminium tube whose internal diameter is 8mm at 0 degree c … elcius.Calculate what change in temperature to produce channel whose cross section equal to 1 mm
Answer:
change in temperature is a decrease by 268.734 K
Explanation:
We are given;
Temperature: T1 = 0°C = 273 K
Internal diameter; d1 = 8mm
Final diameter; d2 = 1 mm
To solve this, we will use Charles law formula since pressure is constant.
Thus;
V1/T1 = V2/T2
Where T2 is the final temperature.
Now, V1 and V2 are volume
Volume is given by: V = area x height
We are told the cross section is equal except for the diameter.
Thus;
V1 = A1 × h
V2 = A2 × h
Thus;
(A1 × h)/T1 = (A2 × h)/T2
h will cancel out and making T2 the subject, we have;
T2 = (A2 × T1)/A1
A2 = π(d2)²/4
A1 = π(d1)²/4
Thus;
T2 = [(π(d2)²/4) × T1]/(π(d1)²/4)
π and 4 will cancel out to givw;
T2 = ((d2)²× T1)/(d1)²
T2 = (1² × 273)/8²
T2 = 273/64
T2 = 4.266 K
Thus;
Change in temperature = T2 - T1 = 4.266 - 273 = -268.734 K
Thus, change in temperature is a decrease by 268.734 K
How many kilometers in 487,320 meters? If there are 1,000 meters in one kilometer?
Answer:
48.732
Explanation:
Just move the denominator 3 times for the 0s in 1000.
Photons with the highest energy have the ____
A. strongest positive charge
B. longest period
C. highest amplitude
D. shortest wavelength
Answer:
D. shortest wavelength
Explanation:
Photons with the highest energy have the shortest wavelength. The shorter the wavelength, the higher the energy of a photon.
A photon is a quantity that transmits electromagnetic energy from one place to the other.
Gamma rays have photons that transmits the highest amount of energy. The rays have the shortest wavelength and highest frequency of all electromagnetic radiations.Energy, wavelength and frequency of a photon are connected using the expression:
E = h f = [tex]\frac{hc}{wavelength}[/tex]
E is the energy
h is the Planck's constant
f is the frequency.
SAT QUESTION // A capacitor is connected to a variable power supply with potential V. Determine the effect on the charge stored on the capacitor if the potential of the power supply is cut in half.
Answer:
decrease by a factor of 2
What is the velocity of a wave with a frequency of 930 Hz and a wavelength of 0.50 m?
Answer:
Hi, thank you for posting your question here at Brainly.
To find the velocity of light or any electromagnetic wave, we use the equation: v = wavelength * frequency. Substituting,
v = 0.5 m * 930 1/s
v = 465 m/s
Brainiest please
Explanation:
