posted by sahan on .
"A 2.5-kg block slides down a 25 degree inclined plane with constant acceleration. The block starts from rest at the top. At the bottom, its velocity reaches 0.65 m/s. The length of the incline is 1.6m.
a) What is the acceleration of the block?
b) What is the coefficient of friction between the plane and the block?
c) Does the result of either (a) or (b) depend on the mass of the block?
Collage or College? Please clarify the School Subject:
What kind of HELP do you need? You need to be specific when asking questions here.
If all you do is post your entire assignment, nothing will happen since no one here will do your work for you. But if you are specific about what you don't understand about the assignment or exactly what help you need, someone might be able to assist you.
First, quantify the given data in terms of symbols:
Length of inclined plane, S = 1.6m
inclination, θ =25°
mass of block, m = 2.5 kg
Initial velocity, u = 0 m/s
Final velocity, v = 0.65 m/s
acceleration = a m/s² (along incline)
coefficient of kinetic friction = μ
Look up your class notes or textbook and be familiar with the formulas required in kinematics of uniform accelerations, and inclined planes.
The approach could be:
1. calculate the net acceleration using the formula
2aS = v²-u²
2. Draw a free body diagram of the block, indication the direction and magnitude of the following forces:
weight due to gravity = mg (downwards)
Normal component of weight = mg*cos(θ) normal to inclined plane
downward component of weight F2= mg*sin(θ) (parallel to inclined plane, downwards)
frictional resistance, Fk= μN (in direction opposite to F2)
Therefore F=F2-Fk is the net force causing the calculated acceleration.
By equating F=ma, μ can be solved for.