Name
Period
Date
Energy Worksheet 7
 k  0.20
System =
1. A 200. kg box is pulled at a constant speed of 3.0 m
by the little engine. The box
s
moves a distance of 2.5 m across a horizontal surface.
a. Draw a force
b. Calculate the normal
c. Calculate the force of
diagram of all forces
force acting on the box.
kinetic friction acting on
acting on the box.
the box.
d. What is the force of
tension acting on the
box? How do you
know?
e. How much energy does
the engine transfer into
the system?
f. Calculate the amount of
energy dissipated by
friction.
g. Construct a quantitative energy bar graph/flow diagram for this situation.
Energy Flow
Initial
Final
Diagram
Ek Eg Ee
E k Eg Ee E d i s s
0
0
f. How far could the box be pulled at constant velocity with the expenditure of
8 000 J of energy?
Energy WS 7
page 2
100. N
30.
50. kg
 k  0.15
2. A person pulls a 50. kg box from rest a distance of 10. m with a force of 100. N at
30. as in the diagram above.
a. Draw a force
b. Write a force equation
c. Calculate the force of
diagram of all the
for the vertical forces
kinetic friction acting on
forces acting on the
and then calculate the
the box.
box.
normal force acting on
the box.
d. How much energy is dissipated by
friction in the pulling process?
e. How much energy is transferred by the
person pulling the box? (Energy
transferred by the process of working)
f. 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
Energy WS 7
page 3
3. Pete Zaria applies a 4.0 N force to a 1.0 kg mug of root beer to accelerate it over a
distance of 1.0 m along the counter top. The coefficient of kinetic friction between the
mug and the counter top is 0.25. Define the system, and then complete the energy
bar graph/flow diagram quantitatively. Determine the mug’s final velocity.
System
Initial
Ek Eg Ee
0
Energy Flow
Diagram
Ek
0
Final
Eg Ee E d i s s