Name
Period
Date
Energy: Worksheet 1
1. A 5.0 g marble is fired vertically upward using a spring gun. The spring must be
compressed 8.0 cm if the marble is to just reach a target 20. m above the marble’s
position on the compressed spring.
a. Construct a quantitative energy bar graph of the situation.
System =
Energy Flow
Initial
Final
D
i
a
g
r
a
m
Ek Eg Ee
E k Eg Ee E d i s s
0
0
b. What is the spring constant of the spring?
2. You are driving your 1200 kg car at 40. m
when you see a state trooper with a radar
s
gun so you hit the brakes to slow down to 29 m , just below the local speed limit.
s
The coefficient of kinetic friction between the car and the ground is 0.5306.
a. Construct a quantitative energy bar graph of the situation.
System =
Energy Flow
Initial
Final
D
i
a
g
r
a
m
Ek Eg Ee
E k Eg Ee E d i s s
0
b. How far did you move while slowing down?
0
Energy: Worksheet 1
page 2
3. A 60. kg student jumps from the 10. m platform into the pool below.
a. Construct a quantitative energy bar graph of the situation from the moment she
leaves the platform until she reaches the water.
System =
Energy Flow
Initial
Final
D
i
a
g
r
a
m
Ek Eg Ee
E k Eg Ee E d i s s
v 0
i
0
0
12 m
10. m
b. How fast is she moving when she hits the water below?
2.0 m
c. Construct a quantitative energy bar graph of the situation from the moment she
leaves the platform until she stops 2.0 m below the water.
System =
Energy Flow
Initial
Final
D
i
a
g
r
a
m
Ek Eg Ee
E k Eg Ee E d i s s
0
0
d. What force does the water exert on her if she comes to a stop in 2.0 m? How
many g's does she experience? (How many times her weight is this force?)
Energy: Worksheet 1
page 3
100. N
4. A person pulls a 50. kg box from rest
with a force of 100. N at 30. .
a. Draw a force diagram for the
box.
30.
50. kg
 k  0.15
b. How much energy is transferred by the
person pulling the box a distance of
10. m ? (Energy transferred by the
process of working)
c. How much energy is dissipated by
friction in the pulling process?
d. What is the % dissipated in this case?
Where does this energy “go”?
e. How fast is the box moving after it has been pulled 10. m ? Construct a
quantitative energy bar graph/flow diagram for this situation, accounting for all
the energy stored and transferred in the process.
Energy Flow
Initial
Final
D
i
a
g
r
a
m
Ek Eg Ee
E k Eg Ee E d i s s
0
0