https://session.masteringphysics.com/problemAsset/1000297048/23/Turorial05_Probl
ID: 1354980 • Letter: H
Question
https://session.masteringphysics.com/problemAsset/1000297048/23/Turorial05_Problem03_image1.jpg
A 5.0-kg block is launched up a rough ramp with an initial speed v0 = 4.5m/s at the bottom of the ramp. The block reaches the top of the ramp and continues on the level section. The coefficient of kinetic friction between the block and the ramp is 0.16. You will find the speed of the block when it reaches the top of the ramp in TWO WAYS.
a) Find the work done by the normal force.
b)Calculate the work done by the gravitational force. Keep three digits.
c)Calculate the work done by the kinetic frictional force. Keep two decimal places.
d)Calculate the TOTAL work done by ALL the forces exerted on the block. Keep three digits.
e)Apply the Work-KE theorem to find the speed of the block when it reaches the top of the ramp. Keep two decimal places.
Explanation / Answer
Here ,
a) as the normal force is perpendicular to the motion ,
hence , work done by the normal force is Zero
b)
Work done by gravitational force = - mgh
Work done by gravitational force = - 5 * 9.8 * 0.52
Work done by gravitational force = -25.5 J
the Work done by gravitational force is -25.5 J
c)
work done by kinetic frictional force = -uk * mg * sin(theta)
work done by kinetic frictional force = - 0.16 * 5 * 9.8 * sin(30)
work done by kinetic frictional force = -3.92 J
the work done by kinetic frictional force is -3.92 J
d)
total work done = -25.5 - 3.92
total work done = -29.42 J
the total work done is -29.42 J
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.