Solve the two folling problems using kinematic equation. a) A block is sliding d
ID: 2124903 • Letter: S
Question
Solve the two folling problems using kinematic equation.
a) A block is sliding down a frictionless horizontal plane, that is inclined by angle theta. What is the acceleration of the block? What is the velocity of the block after it moves from rest a distance Xo down the plane?
b) If the coefficient of static friction between the block and the plane in the first part (a) is (s=0.4) at what angle will the block start sliding if it is initially at rest.
c)If the angle of coefficient of kinetic friction is .3, find the accelleration of the block when the inclined angle of the plane is 30 degrees.
Explanation / Answer
1) acceleration of the block = g sin (theta)
v^2 = 2aX0
Velocity = sqrt( 2X0g sin theta)
2) mg sin (theta) = 0.4 mg cos (theta)
tan (theta) = 0.4
theta = 21.8
angle will the block start sliding = 21.8
3)
Accelration = g sin theta - 0.3 g cos theta = g(0.24) = 0.24 g = 2.356 m/s^2