By looking at a moving object you can easily see its position
and have a sense of its velocity; acceleration is harder. You will use a very
simple accelerometer to see the effect of acceleration. A thin rectangular box
is filled part way with water (maybe with added food coloring).
(a) Place the accelerometer on the table. Sketch the water in the accelerometer
when it is at rest. What is the acceleration? Use the non-permanent pen provided
to mark the level of the water for this case.
(b) Describe the water when the object moves at constant velocity. Does the
direction of the velocity have any effect? Sketch the accelerometer and water
level. What is the acceleration?
(c) Describe the water when the object is accelerating to the right. (Push with
your hand.) Sketch the accelerometer and water level.
(d) Describe the water when the object is accelerating to the left. (Push with
your hand.) Sketch the accelerometer and water level.
(e) Predicting Acceleration
Consider a cart rolling up tilted ramp, due to a push, then rolling back down:
(a) What do you think the direction of the acceleration is as it rolls up the
ramp (no longer being pushed, hand not touching)?
up the ramp down
the ramp other
(Circle one.)
What do you think the direction of the acceleration is when the cart is at its
maximum height?
up the ramp down
the ramp other
(Circle one.)
What do you think the direction of the acceleration is as it rolls down the
ramp?
up the ramp down
the ramp other
(Circle one.)
(f) Get a track and cart. Incline the track at a small angle. Clamp the accelerometer to the “flag” so that the water level in the accelerometer is horizontal when put on the cart on the track. Re-mark this with the non-permanent pen. Give the cart a small push up the track and draw the water level for each case (with hand no longer touching), filling in the table below.
| Cart moving uphill | Cart at maximum height | Cart moving downhill | |
| Sketch water level |
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| Direction of acceleration |
This page maintained by Anne G. Young. Last modified 17-Dec-2003 .