Physics 105, Fall Term, 2009

Reading: Chapters 7.4

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1) Centripetal acceleration is the linear acceleration experienced by a rotating object.

2) Centripetal force is the force that keeps an object in rotational motion.

Go back to: http://phet.colorado.edu/sims/rotation/rotation_en.jnlp and click on the 'Rotational' tab at the very top of the applet.

Change the graph settings to show centripetal acceleration by clicking the 'θ, ω, a' bubble. Start with the ladybug close to the center of the rotating platform and change the angular velocity to 90 degrees per second and press 'Go'. While the platform is spinning move the lady bug out toward the edge of the platform. How does this affect centripetal acceleration?

Increases centripetal acceleration Decreases centripetal acceleration Centripetal acceleration remains the same

What is the direction of the centripetal acceleration vector?

The direction of centripetal acceleration is always linearly inward, toward the center of the circle.

Since the ladybug has a mass, there is a force associated with this acceleration called the centripetal force. What is the direction of the centripetal force?

The direction of centripetal force is the same as the direction of the centripetal acceleration. It is always linearly inward, toward the center of the circle.

If the beetle was swapped for the lady bug (it has a greater mass), how would the centripetal force be affected?

Increases centripetal force Decreases centripetal force Centripetal force remains the same

When experiencing a constant angular velocity, like on a spinning ride at a theme park, you are pushed out from the center of the circle. What causes this to happen?

Centripetal force Centrifugal force Frictional force Inertia

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Was there anything that you didn't understand in the reading assignment? What was confusing to you?

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