400 N pushes on a 25-kg box. Starting from rest, the box achieves
a velocity of 2.0 m/s in a time of 4.0 s. Find the coefficient of kinetic friction between box and
floor.
Answer:
The kinetic coefficient of friction between box and floor is 0.443.
Explanation:
Let suppose that the box is accelerated uniformly, the acceleration ([tex]a[/tex]), measured in meters per square second, is determined by the following kinematic formula:
[tex]a = \frac{v_{f}-v_{o}}{t}[/tex] (1)
Where:
[tex]v_{o}[/tex], [tex]v_{f}[/tex] - Initial and final speeds of the box, measured in meters per second.
[tex]t[/tex] - Time, measured in seconds.
If we know that [tex]v_{o} = 0\,\frac{m}{s}[/tex], [tex]v_{f} = 2\,\frac{m}{s}[/tex] and [tex]t = 4\,s[/tex], then the acceleration experimented by the box is:
[tex]a = \frac{2\,\frac{m}{s}-0\,\frac{m}{s} }{4\,s}[/tex]
[tex]a = 0.5\,\frac{m}{s^{2}}[/tex]
Based on the body diagram, we proceed to form the equations of equilibrium:
[tex]\Sigma F_{x} = P\cdot \cos \theta -\mu_{k}\cdot N = m\cdot a[/tex] (1)
[tex]\Sigma F_{y} = N - m\cdot g - P\cdot \sin \theta = 0[/tex] (2)
Where:
[tex]P[/tex] - Magnitude of the force exerted on the box, measured in newtons.
[tex]\theta[/tex] - Direction of the force exerted on the box, measured in sexagesimal degrees.
[tex]\mu_{k}[/tex] - Kinetic coefficient of friction between box and floor, dimensionless.
[tex]N[/tex] - Normal force from the floor to the box, measured in newtons.
[tex]m[/tex] - Mass of the block, measured in kilograms.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
Now we proceed to solve the system of equation for the kinetic coefficient of friction between box and floor:
By (1)
[tex]\mu_{k}\cdot N = P\cdot \cos \theta -m\cdot a[/tex]
[tex]\mu_{k} = \frac{P\cdot \cos \theta - m\cdot a}{N}[/tex]
By (2)
[tex]N = m\cdot g +P\cdot \sin \theta[/tex]
And then, we get the resulting expression:
[tex]\mu_{k} = \frac{P\cdot \cos \theta - m\cdot a}{m\cdot g + P\cdot \sin \theta}[/tex] (3)
If we know that [tex]P = 400\,N[/tex], [tex]\theta = 50^{\circ}[/tex], [tex]m = 25\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]a = 0.5\,\frac{m}{s^{2}}[/tex], then the kinetic coefficient of friction between box and floor is:
[tex]\mu_{k} = \frac{(400\,N)\cdot \cos 50^{\circ}-(25\,kg)\cdot \left(0.5\,\frac{m}{s^{2}} \right)}{(25\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)+(400\,N)\cdot \sin 50^{\circ}}[/tex]
[tex]\mu_{k} = 0.443[/tex]
The kinetic coefficient of friction between box and floor is 0.443.
The kinetic coefficient of friction between box and floor is 0.443.It is the ratio of friction force and the normal recation force.
What is the friction force?It is a type of opposition force acting on the surface of the body that tries to oppose the motion of the body. its unit is Newton (N).
Mathematically it is defined as the product of the coefficient of friction and normal reaction.
The given data in the problem is;
F is the force =400 N
m is the mass of box= 25-kg
u is the velocity starting from rest=0
v is the velocity achieved = 2.0 m/s
t is the time = 4.0 s.
[tex]\rm \mu[/tex] is the coefficient of kinetic friction between box and floor.
The aceleration is found as;
[tex]\rm a= \frac{v_f-v_u}{t} \\\\ \rm a= \frac{2-0}{4} \\\\ \rm a= 0.5 m/sec^2[/tex]
The normal reaction force is find as;
[tex]N= mg +P sin \theta[/tex]
The cofficient of the kinetic coefficient of friction between box and floor;
[tex]\rm \mu_k = \frac{Pcos \theta - ma }{N } \\\\ \rm \mu_k = \frac{Pcos \theta - ma }{ mg +P sin \theta } \\\\ \rm \mu_k = \frac{400 cos 50^0 - 25 \times 0.5 }{ 25 \times 9.81 +400 \times sin 50^0 } \\\\ \rm \mu_k =0.443[/tex]
Hence he kinetic coefficient of friction between box and floor is 0.443.
To learn more about the friction force refer to the link;
https://brainly.com/question/1714663
what is the correct answer?
Answer:
The value of k is -4. Third choice
Explanation:
The Polynomial Remainder Theorem
It states that the remainder of the division of a polynomial f(x) by (x-a) is equal to f(a).
We are given the polynomial:
[tex]p(x)= x^3+kx^2+x+6[/tex]
And we also know x+1 is a factor of p(x). If x+1 is a factor of p(x), then the remainder of the division of p(x) by x+1 is zero.
Applying the remainder theorem for a = -1:
[tex]p(-1)= (-1)^3+k(-1)^2+(-1)+6=0[/tex][tex]-1 + k - 1 + 6 = 0[/tex]
Solving for k:
[tex]k = 1 + 1 - 6[/tex]
[tex]\boxed{k = -4}[/tex]
The value of k is -4. Third choice
Anyone.... help with this two questions...
derive formula of kinetic energy of particular having mass volume and velocity of dimensional analysis
Answer:
E=1/2kmv^2
Explanation:
To get the formula...
The dimension of energy is [ M^1 L^2 T^-2]
The dimension of mass [M]=[M^1 L ^0T ^0]
Dimension of velocity[V]=[M ^0 L ^1 T ^−1]
Let [E]=k[M] ^x[V] ^y
K is constant and it remain a dimensionless quantity.
Therefore, M ^1L ^2T ^−2]=k[M ^1L ^0T ^0] x[M ^0L ^1 T ^−1] y
So, x=1,y=2
E= Kmv^2
K=1/2
Therefore E is 1/2kmv^2.
A 3.0-kg mass is moved at a constant speed by a force of 6.0 N. What is the change in the kinetic energy of the mass as it moves over a distance of 4.0 m in the direction of the force
Answer:
The change in kinetic energy is zero (0).
Explanation:
Given;
mass of the object, m = 3.0 kg
applied force, f = 6 N
distance through the object is moved, d = 4.0 m
The acceleration of the object is calculated as;
f = ma
a = f / m
a = (6) / 3
a = 2 m/s²
The constant speed through which this object is moved is calculated as;
v² = u² + 2ad
v² = 0 + 2 (2)(4)
v² = 16
v = √16
v = 4 m/s
The change in kinetic energy is calculated as;
ΔK.E = K.E(final) - K.E(initial)
ΔK.E = ¹/₂mv₂² - ¹/₂mv₁²
v₂ = v₁ = v (since the mass was moved at a constant speed; v)
ΔK.E = ¹/₂mv² - ¹/₂mv²
ΔK.E = 0
Therefore, the change in kinetic energy is zero (0).
why is the horizontal component of a velocity remains constant in horizontal and inclined projection
Answer:
This is because there is no acceleration in the horizontal direction
Explanation:
This is because, the only acceleration affecting the object in horizontal and inclined projection is the acceleration due to gravity, which is directed the vertical downward direction. There is a velocity change only in the vertical direction and none in the horizontal direction because, there is no acceleration in the horizontal direction. So, its velocity remains constant.
Which of the following exhibit parabolic motion?
a flat rock skipping across the surface of a lake
a three-point shot in basketball
an airplane in flight at a steady cruising altitude
a ball bouncing across the room
a life preserver dropped from a stationary helicopter
Answer:
A
Explanation:
Hopefully this helps
is love really a feeling or is it just mental?
Answer:
i really don't know anything about love ,because i have never experienced this .but love is just a person feeling and emotion about someone ,that we name as love.
Explanation:
An icicle falls off of a skyscraper from rest and falls for 34 seconds. How far did the icicle fall? Show all work and units. (a = g = 9.81 m/s^2) *
Explanation:
u = 0.0m/s
t = 34s
a = 9.81m/s²
Using Kinematics,
s = ut + 0.5at²
= 0 + 0.5(9.81)(34)²
= 5,670.18m.
Please help me with this.
Question 7 of 10 What causes magnetic domains? O A. Magnetic poles of magnets attracting each other O B. Electricity moving through iron O C. Magnetic fields of atoms aligning D. Iron being placed near a magnet.
Answer:
C. Magnetic fields of atoms aligning
Answer:
c
Explanation:
a pex
Scientists are studying a moving glacier. To monitor the flow of the glacier, they place a series of five markers, A, B, C, D, and E, in a straight line across the path of flow. A and E are closest to the edges of the glacier. C is in the center of the glacier. B and D are between A and C and C and E respectively. How would the scientists predict the motion of each of the markers relative to the edges of the valley down which the glacier flows? What pattern would they predict in the markers over time?
Answer: c a d b
Explanation:
Glaciologists use Glen–Nye Flow Law, to predict the movements of glaciers thus, The pattern they predict in the markers over time would be C D A B.
How would the scientists predict the moving glacier of the markers relative to the edges of the valley down which the glacier flows?In some parts of the world, glaciers are an important natural resource because the nature and behaviour of glaciers are an impact the hydrologic, geologic, and ecological systems of their immediate location.
Due to this, Glaciologists monitor and try to predict the movement and morphology of glaciers.
One of the techniques used by "Glaciologists" in the monitoring and prediction of glaciers in the use of markers.
The movement of markers is measured relative to the edges of the valley down which the glacier flows.
Thus, The movement of the markers are then predicted using the Glen–Nye Flow Law.
The pattern they predict in the markers over time would be C D A B.
Learn more about the glacier here;
https://brainly.com/question/17743729
#SPJ2
What is the random walk?
Answer:
In mathematics, a random walk is a mathematical object, known as a stochastic or random process, that describes a path that consists of a succession of random steps on some mathematical space such as the integers.
Explanation:
need ASAP WILL MARK BRANLIEST
Answer:
pls refer to attachments
All models have a limitations True or false
Answer:
The answer is True.
A 1000-kg car comes to a stop without skidding. The car's brakes do 50,000 J of work to stop the car. Which of the following was the car's velocity when the brakes were initially applied?
Answer:
10m/s
Explanation:
Is the gravity on the moon and earth the same and why are they the same or different
Who was Alfred Wegener and what did he theorize?
Answer:
Who was Alfred Wegener: He was a German meteorologist and geophysicist
What did he theorize: he theorized continental drift and he also explained how all 7 continents were once together( aka Pangaea) on earth over millions of years ago.
Hope this helped a little!
Suggest a form of renewable energy that could be used to power an electric ticket machine that only needs to work during daylight hours.
Answer:
solar panel or wind turbine
Explanation:
Because solar panel gives energy to electricity by sun and wind turbine gives energy through wind and both are renewable
Renewable energy that could be used to power an electric ticket machine that only needs to work during daylight hours is solar energy.
What is solar energy?Solar energy is the term for solar radiation that can create heat, trigger chemical reactions, or create electricity. The total solar energy incident on Earth is far greater than the global energy needs at the moment and in the future. This highly distributed source has the ability to meet all future energy demands if properly exploited.
Due to its limitless supply and lack of pollution, solar energy is predicted to become a more appealing renewable energy source in the twenty-first century than the finite fossil fuels coal, petroleum, and natural gas.
Although sunlight is by far the most potent energy source that Earth receives from the Sun, its intensity at the surface of the planet is actually rather modest.
This is primarily due to the massive radial radiation propagating from the far-off Sun. Earth's atmosphere and clouds, which absorb or scatter as much as 54% of the incoming sunlight, cause a comparatively small additional loss.
Learn more about solar energy here:
https://brainly.com/question/9704099
#SPJ2
PLEASE ANSWER - WILL MARK BRAINLIEST - THANKS
List three scientific ideas, discoveries, concepts, or issues that interest you.
Answer:
Evolution, Big Bang Theory and Cell theory.
Explanation:
These theories interest me because they talk about life and how life started.
A bicyclist initially at rest, begins pedaling and gained speed steadily for 4.80s during which she covers 37.0m What was her final speed?
Answer:
The final speed of the bicyclist is 15.44 m/s.
Explanation:
Given;
initial velocity, u = 0
time of motion, t = 4.8 s
distance covered, d = 37.0 m
The acceleration of the bicyclist is calculated as;
d = ut + ¹/₂at²
37 = 0 + ¹/₂(4.8)²a
37 = 11.52a
a = 37 / 11.5
a = 3.22 m/s²
The final speed of the bicyclist is given as;
v² = u² + 2ad
v² = 0 + 2(3.22)(37)
v² = 238.28
v = √238.28
v = 15.44 m/s
Therefore, the final speed of the bicyclist is 15.44 m/s.
please help..................
Answer:
PART A
In a solid
The attractive forces keep the particles together tightly enough so that the particles do not move past each other. ... In the solid the particles vibrate in place. Liquid – In a liquid, particles will flow or glide over one another, but stay toward the bottom of the container.
In a liquid
Particles are quite close together and move with random motion throughout the container. Particles move rapidly in all directions but collide with each other more frequently than in gases due to shorter distances between particles.
A gas
The particles move rapidly in all directions, frequently colliding with each other and the side of the container. With an increase in temperature, the particles gain kinetic energy and move faster.
PART B
The molecules are continually colliding with each other and with the walls of the container. When a molecule collides with the wall, they exert small force on the wall The pressure exerted by the gas is due to the sum of all these collision forces. The more particles that hit the walls, the higher the pressure.
Explanation:
GOOD LUCK!!! :)
Please help I will send pics in return or I will mark brainliest (depending on what u want) for a good attempt and explanation.
The answer would have to be 8.47 m/s/s because the backwards pull + the rate of speed it is going would have to be added to get the answer to compensate for the backwards pull
A car is stopped for a traffic signal. When the light turns green, the car accelerates, increasing its speed from zero to 5.27 m/s in 0.833 s. What linear impulse and average force does a 69.8 kg passenger in the car experience
Answer:
See explanation
Explanation:
From Newton's law; the rate of change of momentum is proportional to the impressed force. Hence;
F.t = mv- mu
F= force
t= time
m= mass
V= final velocity
u = initial velocity
since u = 0, mv= 0
F= MV/t
F= 69.8 × 5.27/0.833
F= 442 N
Impulse = Ft= 442 × 0.833= 368 Ns
given a force of 88n and an acceleration of 4m/s2 what is the mass
Answer:
The mass is 22 kilograms
Explanation:
[tex]F=ma[/tex]
[tex]88N = m(4m/s/s)[/tex]
[tex]m=\frac{88N}{4m/s^{2} }[/tex]
[tex]m=22kg[/tex]
The variables for Part I of this experiment include whether or not the car hits the barrier and the distance that the washers travel. Use the drop-down menus to identify the independent and dependent variables.
The independent variable, the one that is intentionally manipulated, is
____.
The dependent variable, the one that you measure the response in, is
___.
Answer:
1. An encounter with the barrier
2. The distance traveled by the washer.
Explanation:
Answer:
Peep above me is correct
1.An encounter with the barrier
2.The distance traveled by the washer
Explanation:
got it right on edge2020 have a nice day peeps ^w^
2km south is a measure of what
The answer Is kilometers
Please help me on this!!!
Two balls, ball A and ball B, are dropped from the same height onto the same surface. If ball A rebounds to a higher height than ball B then:(3) A. ball A is more elastic than ball B. B. ball B is more elastic than ball A. C. not enough information is given to determine which ball is more elastic.
Answer:
its b
Explanation:
which two solids most likelyhave the lowest melting point??
Answer:
The two solids in the right boxes
Explanation:
The two solids in the right boxes will most likely have the lowest boiling point and this can be inferred from their molecular configuration.
Boiling point as physical change is determined by the intermolecular forces within a compound. Very strong intermolecular interactions will be difficult to break. This is shown by the two models in the left boxes. For the right boxes, the connections are very weak and they will have low boiling points.Give an example of the Law of Conservation of Energy. Explain your example
Answer: The law of conservation of energy can be seen in these everyday examples of energy transference: Water can produce electricity. Water falls from the sky, converting potential energy to kinetic energy. This energy is then used to rotate the turbine of a generator to produce electricity.
Explanation: Thats what we learned
