Download CENTRIPETAL ACCELERATION ACTIVITY

Name: ________________________________________ Date: _______________ Period: __________
Circular Motion Inquiry Investigation
Review: Circle the appropriate italicized response.
 Speed is a scalar / vector quantity that measures magnitude only / both magnitude and direction.

Velocity is a scalar / vector quantity that measures magnitude only / both magnitude and direction.

Acceleration is a scalar / vector quantity that measures how an object’s speed / velocity is changing over
time.

Net force and acceleration are always / never / sometimes pointing in the same / opposite directions.
Part 1: Set-up
 Go to physicsclassroom.com. Click on “Shockwave Studios” (on the left). Scroll down and click on “Uniform
Circular Motion.”
 Click “Velocity” under “Vector Display”. Click “Start”. Let the simulation make a complete revolution.
Part 1: Conceptual Investigation
1. Draw a picture below showing the ball at two separate locations. Draw and label the direction of the
velocity at these two locations on your drawing.
2. As the ball revolves, what direction is the velocity vector always pointing relative to the circle?
3. Look at the size of the velocity vector as the ball moves in a circle. Does the magnitude change as the ball
moves in a circle? What does this tell us about the speed of the object as it moves around the circle?
4. Now, click “acceleration” under “vector display.” Draw a picture below showing the ball at two separate
locations. Draw and label the direction of the acceleration vector at these two locations on your drawing.
5. As the ball revolves, what direction is the acceleration vector always pointing relative to the circle?
6. In order for an object to accelerate, its velocity must be changing in some way. In the case of circular
motion, what part of an object’s velocity is changing – the speed or the direction?
7. Using your knowledge of net force and acceleration, what direction must the net force be acting on the
ball when it is moving in a circle?
8. On the left side of the screen, increase the mass.
a. What effect does increasing the mass have on acceleration?
b. What effect does increasing the mass have on the net force?
9. On the left side of the screen, now reduce the mass.
a. What effect does decreasing the mass have on acceleration?
b. What effect does decreasing the mass have on the net force?
10. Now, keep mass and radius constant, and increase the velocity of the ball.
a. What effect does increasing the velocity have on acceleration?
b. What effect does increasing the velocity have on net force?
11. Decrease the velocity of the ball (keeping mass and radius constant still).
a. What effect does decreasing the velocity have on acceleration?
b. What effect does decreasing the velocity have on net force?
12. Now, keep mass and velocity constant, and increase the radius of the ball.
a. What effect does increasing the radius have on acceleration?
b. What effect does increasing the radius have on net force?
13. Decrease the radius of the ball (keeping mass and velocity constant still).
a. What effect does decreasing the radius have on acceleration?
b. What effect does decreasing the radius have on net force?
Part 1: Analysis
14. Mass and acceleration are directly / inversely / not related while mass and force are
directly / inversely/ not related when objects are moving in a circle.
15. Velocity and acceleration are directly / inversely / not related while velocity and force are
directly / inversely/ not related when objects are moving in a circle.
16. Radius and acceleration are directly / inversely / not related while radius and force are
directly / inversely/ not related when objects are moving in a circle.
17. In the diagram to the right, a variety of positions are shown for an object moving
clockwise in a circle. At each location, draw and label the velocity and acceleration
vectors.
Part 2: Quantitative Investigation
18. Now that you have qualitatively investigated the effects mass, radius, and velocity on acceleration and
force for an object moving in a circle, let’s now investigate these relationships quantitatively. Change the
variables r, m, and v to run 5 trials and record the data in the table below for each trial.
Trial
1
r(m)
v (m/s)
m (kg)
a (m/s/s)
∑F (N)
2
3
4
5
19. Using your data table above, determine the mathematical equation for the relationship between velocity,
acceleration and radius (i.e. find the equation). Use one of your trials data to support your result.
Formula
Supporting Evidence
Trial 1:
20. Using your data table above, determine the mathematical equation for the relationship between velocity,
mass, radius and net force (i.e. find the equation). Use one of your trials data to support your result.
Formula
Supporting Evidence
Trial 1:
Conclusion
21. Explain how a moving object can experience a non-zero net force yet the speed of the object (or
magnitude of velocity) can remain constant.
22. For the same speed, the acceleration of the object varies _____________ (directly, inversely) with the
radius of curvature.
23. For the same radius of curvature, the acceleration of the object varies _____________ (directly, inversely)
with the speed of the object.
24. As the speed of an object is doubled, the acceleration is __________________ (one-fourth, one-half, two
times, four times) the original value.
25. As the speed of an object is tripled, the acceleration is __________________ (one-third, one-ninth, three
times, nine times) the original value.
26. As the radius of the circle is doubled, the acceleration is __________________ (one-fourth, one-half, two
times, four times) the original value.
27. As the radius of the circle is tripled, the acceleration is __________________ (one-third, one-ninth, three
times, nine times) the original value.