Physics 011
A of
PQ#6A
Chapter 6: Work and Energy
Practice Questions
1. 

Two men,
Joel and Jerry, push against a wall. Jerry stops after 10 min, while Joel is
able to push for 5 min longer. Compare the work against the wall they each
do. The formula for work does not involve the time. Review Section 61 in Giancoli. 



2. 

Which of
the following graphs illustrates Hooke's Law (the spring force)? Review Section 64 in Giancoli. 



3. 

A simple pendulum, consisting of a
mass m and a string, swings upward, making an angle q with the vertical. The
work done by the tension force is 



4. 

What is the mass of the pendulum 'bob' in the figure? The potential energy is mgh. Review Section 64 in Giancoli. 



5. 

What is the total mechanical energy, ME, of the pendulum? 



6. 

What is the maximum kinetic energy of the pendulum? This is the minimum kinetic energy. Review Section 67 in Giancoli. 



7. 

What is the potential energy, PE, at point B and D? This would be the energy at the top. Review Section 67 in Giancoli. 



8. 

At point B and D what is the relationship between the kinetic energy, KE
and the potential energy, PE? KE+PE=constant. Review Section 67 in Giancoli. 



9. 

What is the speed of the pendulum at point B and D? That is the speed at the top. Review Section 67 in Giancoli. 



10. 

What is the speed of the pendulum at point C? 



11. 

A simple pendulum, consisting of a
mass m, is attached to the end of a 1.5 m length of string. If the mass is
held out horizontally, and then released from rest, its speed at the bottom
is 



12. 

A 4kg
mass moving with speed 2 m/s, and a 2kg mass moving with a speed of 4 m/s,
are gliding over a horizontal frictionless surface. Both objects encounter
the same horizontal force, which directly opposes their motion, and are
brought to rest by it. Which statement best describes their respective
stopping distances? The work (W=F*D) equals the change in kinetic energy. Review Example 65 in Giancoli. 



13. 

A 4kg
mass moving with speed 2 m/s and, an otherwise identical, 2kg mass moving
with a speed of 4 m/s, are gliding over a horizontal surface with friction
and are brought to rest by it. Which statement best describes their
respective stopping distances? 



14. 

A force that object A exerts on object B is observed over a 10second
interval, as shown on the graph. How much work did object A do during that 10
s? The force is always positive (in the direction of motion). Review Section 64 in Giancoli. 



15. 

A force that object A exerts on object B is observed over a 10second
interval, as shown on the graph. What is the average power output of A into
B? Review Section 610 in Giancoli. 



16. 

The resultant force you exert on a shopping cart, for a 10 s period, is
plotted on the graph, shown. How much work did you do during this 10 s
interval? This would be the work if both forces were below the xaxis. Review Section 64 in Giancoli. 



17. 

The resultant force you exert on a shopping cart, for a 10 s period, is
plotted on the graph, shown. Which of the following statements are true? Review Section 610 in Giancoli. 



18. 

How much work was required to bring the 1000kg roller coaster from point
P to rest at point Q at the top of the 50 m peak? 



19. 

If the roller coaster leaves point Q from rest, how fast is it traveling
at point R? Don't forget that there is a 1/2. Review Section 67 in Giancoli. 



20. 

If the roller coaster leaves point Q from rest, what is its speed at point
S (at the top of the 25m peak) compared to its speed at point R? 



21. 

What was
the total work done on you by all the forces in the universe between the time
just before you awoke this morning and right now? Review Section 63 in Giancoli. 



22. 

Two cars,
starting from rest at the same place, travel by different routes to the same
destination. One of the cars passes the other as they drive through it. Which
of the following statements will be true? 



23. 

The work
done by friction, f, The angle is always 180 degrees. Review Section 61 in Giancoli. 



24. 

A 102 kg
man climbs a 5.0 meter high stair case at constant speed How much work does
he do? You probably forgot 'g'. Review Section 64 in Giancoli. 



25. 

A ball is
released, from rest, at the left side of the looptheloop, at the height
shown. If the radius of the loop is R and there is no friction, what vertical
height does the ball rise to on the other side? (LOOPTHELOOP) 
