Name
Period
Date
Energy Worksheet 8
Quantitative Energy Problems
1. A moving cart hits a spring, traveling at 5.0 m
at the time of contact. At the instant
s
the cart is motionless, by how much is the spring compressed?
System = _____________________
m = 8.0 kg
vi = 5.0 m/s
k = 50. N/m
vf = 0
Initial
Final
2. A block is placed on a spring, compressing it 0.30 m . What height does the block
reach when launched by the spring?
System =
m = 500. g
vf = 0
k = 100. N/m
x = 0.30 m
0
Initial
Final
3. A baseball m  140 g  traveling at 30. m moves a fielder's glove backward
s
35 cm when the ball is caught.
a. Construct a quantitative energy bar graph of the situation.
System =
Energy Flow
Initial
Final
Diagram
Ek Eg Ee
E k Eg Ee E d i s s
0
0
b. What was the average force exerted by the glove on the ball?
Energy WS 8
4. A 60. kg student jumps from the 10. m platform at Hartland’s
swimming complex into the pool below.
a. What was the change in the gravitational potential energy of
the diver as she climbed to the top of the 10. m platform?
page 2
vi  0
b. How much Ek does she possess at impact with the water?
10. m
c. Assuming that all of this E g was converted into Ek ,
determine the speed of the diver at impact.
d. Compare the speed and kinetic energy for a 75 kg diver diving from 10. m .
e. How many times greater would be the speed of the 60. kg diver if she dove from
a platform 20. m above the pool?
f. How much higher would the platform have to be in order for her speed to be
twice as great?
Energy WS 8
page 3
5. A spring whose spring constant is 850 N
is compressed 0.40 m . What is the
m
maximum speed it can give to a 500. g ball that lies on a frictionless surface?
k  850
N
m
500. g
6. A bullet with a mass of 10. g is fired from a rifle with a barrel that is 85 cm long. If
the average force exerted by the expanding gas is 5500 N , what speed would the
bullet reach?
7. A 24 kg child descends a 5.0 m high slide and reaches the ground with a speed of
2.8 m . How much energy was dissipated due to friction in the process?
s
24 kg
5.0 m
Energy WS 8
page 4
8. Suppose a robust 10. kg Opus the flightless waterfowl was shot straight up from a
cannon with an initial velocity of  50. m .
s
a. Assuming no air resistance, what is the maximum height he could reach?
b. Suppose that 20.% of his initial Ek were lost due to friction with the air
(air resistance). What is the maximum height he could now reach?
9. A 1500 kg car is traveling at 20. m .
s
a. How much Ek does it have?
b. If the average braking force applied to the car is 6000. N , what distance would it
travel before it came to a stop?
c. If this same average braking force were applied to the car moving at twice the
speed, what would be the stopping distance?