Name_____________________
Period:___
Physics Chapter 5
Power, Pendula, Potential & Kinetic Energy
1. A Vespa motorbike has a kinetic energy of 275,000 J when
traveling at a speed of 18 m/s. What is its mass?
2. A 75 kg bobsled is pushed along a horizontal surface by two
athletes. After the bobsled is pushed for 3.5 seconds starting
from rest, its speed is 6.0 m/s. Find the magnitude of the net
force on the bobsled.
3. Mrs. Sanders has a mass of 75 kg. She is in a swing that is
attached to ropes 2.00 m long. Find her gravitational potential
energy under the following conditions:
a. When the ropes are horizontal
b. At the bottom of the circular arc
4. Robin Hood climbed up the Gallows Oak in Sherwood Forest
to a branch 12 meters above the ground, when he suddenly
spied Maid Marian walking along the path. He got so excited
that he dropped his quiver. If the only vine he could find to
swing down upon that was the right length to scoop her up in
his arms formed a 40 degree angle from the vertical
a. How long is the vine?
b. How far away is Maid Marian from where the quiver
hit the ground?
5. The staples inside a stapler are kept in place by a spring with
a relaxed length of 0.115 m. If the spring constant is 51.0
N/m, how much elastic potential energy is stored in the
spring when its length is 0.150 m?
6. A pendulum bob is released from some initial height such
that the speed of the bob at the bottom of the swing is 1.9
m/s.What is the initial height of the bob?
7. A 2500 kg car requires 5.0 kJ of work to move from rest to
some final speed. During this time, the car moves 25.0 m.
Neglecting friction between the car and the road, find the
following:
a. the final speed
b. the horizontal force exerted on the car
8. Tarzan swings on a 30.0 m long vine initially inclined at an
angle of 37.0with the vertical. What is his speed at the
bottom of the swing if he
a. starts from rest
b. pushes off with a speed of 4.00 m/s
PRACTICE 5E