Download How much work (energy) is needed to lift a 200

Name ______________________________
Date ______________
Chapter 7 HW1: Work and Kinetic Energy
1. How much work (energy) is needed to lift a 200-N object straight up to a height
of 4 meters?
2. How much power is needed to lift the 200-N object to a height of 4 meters in 4
seconds?
3. What is the power output of an engine that does 60,000 J of work in 10 seconds?
3. A 4 kg brick slides a distance (d) of 5m along an icy slope of inclination angle of 30°.
The coefficient of kinetic friction is µk = 0.20. What will be the speed of the brick at the
end of the slope?
Name ______________________________
Date ______________
Chapter 7 HW2: Work and Kinetic Energy
A 2 kg block is accelerated from rest along a horizontal, smooth surface by a force of 5 N
over a distance of 6 m.
a.
b.
c.
d.
Determine the acceleration of the block and the final velocity of the block.
Calculate the work done by the accelerating force.
Find the final velocity of the block if it has an initial velocity of +2 m/s.
If the block is moving with a velocity of 8 m/s, what should the coefficient of
kinetic friction be in order to stop it in the 5 m?
Name ______________________________
Date ______________
Chapter 7 HW3: Work and Kinetic Energy
4. A force of 50 N, applied at an angle of 37º to the horizontal, is required to drag a
block across the table at a constant velocity of 0.7 m/sec.
a. If the coefficient of friction between the block and the table is 0.20, what is
the mass of the block?
b. If the block is pulled for a total of 3 seconds, how much work does the applied
force, F, do?