Apparatus Title: Acceleration Demonstrator

Abstract

Device to demonstrate both direction and magnitude of linear and centripetal acceleration.

• Support required for apparatus: Need clear floor space to drive the car (small room size).
• Approximate size: Length of car, about a foot.
• Does this apparatus require Electrical Power? no (has internal batteries)
• Is this apparatus intended for use with an overhead projector? no
• Will you be present to set up your apparatus? yes
• When do you plan to set up your apparatus? Sunday, July 30 2-4:30 PM

Equipment required to construct apparatus:

Toy car and radio-control unit from Radio Shack, clear plastic tube 1/2" diameter, total length about 4 ft. Elbow joints, glue, fixing hardware.

Item Source/Store Part Number Cost

Total cost...$50.00

Sketch of the apparatus

Description

I have equipped a toy radio-controlled car with two orthogonal accelerometers. These are simple plastic U-tubes filled with colored water. One U-tube is aligned forward and backward, the other sideways. One of the U-tubes is filled with green and the other with red colored water. The top ends of the U-tubes are connected together using clear plastic tubes (this prevents water overflow). Acceleration is demonstrated by running the car. Forward-backward acceleration is evident when the car accelerates from rest, the water level in the forward-backward U-tube moves towards the rear, opposite when the car stops. Centripetal acceleration shows up in the unequal level of water in the sideways U-tube when the car is turning. The magnitude of the accleration is proportional to the height difference of the water level in a U-tube. One can show the independence of the two components of accleration, as well as the magnitudes. Kids also have fun driving the car!