Circular Motion: Chapter 5: Conceptual Homework
Uniform Circular Motion, pg. 109-112
1. Answer the chapter opening questions:
1.
2.
2. If force is acting on an object in the direction of motion of that object then the
object will go in a ____________________ _____________.
3. If an applied force acts at an angle of the motion that an object is going than the
object will go in a _____________________ _____________.
4. Define Uniform circular motion:
5. When an object is moving in a circle at constant speed, the magnitude of the
velocity remains ____________________ but the direction is _______________________
____________________________.
6. A change in direction in a velocity is an ______________________________, thus an object
going around a circle is constantly ___________________.
7. Remember the equation for acceleration is:
8. For determining a change of velocity for a particle moving in a circle draw and
label figures 5-2 A and B below:
9. Define centripetal (radial) acceleration:
10. The equation for change of velocity in circular motion is:
11. The equation for centripetal acceleration is:
12. An object moving in a circle with radius r at constant speed has an acceleration
whose direction is towards the _________________of the circle and whose
magnitude is ___________________________.
13. The greater the speed, the _______________________the velocity changes direction.
14. The greater the radius of the circle the _____________________the velocity changes
direction.
15. Velocity and acceleration vectors are ___________________________ to each other
around the circular path.
16. What is frequency?
17. What is period?
18. How are frequency and period related?
19. In a circle with circumference of 2r, an object travels at constant speed and
travels a distance of 2r in one time around the circle, which gives us the
equation for velocity in the circle as:
20. Read Example 5-1 about the acceleration of a revolving ball. Read the approach,
then try to solve the problem below:
21. Reflection: How did your solution compare to the book? Were you able to solve
the problem correctly? What did you need to do differently?
22. Read example 5-2, Moon’s centripetal force. Think how you would solve the
problem. Solve the problem below.
23. Reflection: How did your solution compare to the book? Were you able to solve
the problem correctly? What did you need to do differently?
Dynamics of Uniform Circular Motion: pg 112-114
1. An object that is moving in a circle must have a _________________
_____________________ acting on it—According to Newton’s _______Law.
2. The equation for the net forces on centripetal acceleration is:
3. Since acceleration is directed toward the center of the circle, the force also must
always be _________________________________.
4. The net force must be constantly changing _______________________ to keep it
directed toward the center of the circle.
5. Define centripetal force:
6. What is “centrifugal” force and why is it a misconception?
7. What would happen if centrifugal force were a true force to objects in circular
motion?
8. Read example 5-3 and the approach, try the example here:
9. Read example 5-4, try this one on your own before you check your answer:
10.
Write a summary of the four steps to problem solving uniform circular motion:
Now try it on your own. Do problems #1, 7 and 13 in your text on a separate piece of paper.