Return to Physics IndexMomentum

Sandra Tucker Crown Fine Arts Academy

2128 S. St. Louis

Chicago IL 60623

(312)534-1680Objective:

This lesson is designed for primary level students. They will observe the

transfer of momentum.Materials Needed:

2 or more pairs of rollerblades

2 cars - each car has a spring attached to the front bumper and velcro attached

to the rear bumper.

a weight (that will fit on one of the cars)

cue balls

cue stick

marbles

stringStrategy:

Begin with a roller blade demonstration. Tell the students they will need to

observe what happens. Students of approximately the same weight will put on

rollerblades and will participate in four demonstrations. (Be sure students

wearing roller blades are also wearing helmets and other protective gear.)

l. One person stands still. The other person skates into him. At the

point when they would collide, they push off from each other.

2. Repeat above, but this time, as they meet they grab on to each other.

3. Both students skate towards each other. When they meet, they push off

from each other.

4. Repeat above, but this time, they grab on to each other.

This entire series can be repeated using one heavier student (or two students

together) and one lighter student. See if the results are the same. If

possible, let all students try these demonstrations with a partner.

Now repeat the demonstration using the 2 cars. The students will observe and

discuss what they see. The teacher can draw the diagrams of the car's movement

on the board.

1. One car moving - one car still. The springs on the cars are facing

each other. Observation: The moving car stops and the still car

moves in the same direction the moving car was going.

2. One car moving - one car still. The velcro on the cars is facing each

other. Observation: The cars stick together and move slowly in the

direction the moving car was going.

3. Both cars moving towards each other. The springs on the cars are

facing each other. Observation: Each car moves in the opposite

direction but slower.

4. Both cars moving towards each other. The velcro on the cars is facing

each other. Observation: The cars stop.

These demonstrations can be repeated putting a weight on one of the cars. Some

of the observations will differ. Students should observe that movement

transfers from one car to the other. This is called the transfer of momentum.

They should also see that the weight of the car (or other object) affects the

speed and direction of the movement.

Now do a demonstration using cue balls. Line up two cue balls. Have a student

hit them with a cue stick so they move in an angle. Use a string to show where

the ball was hit and the path each ball takes. The students should be able to

see a 90 degree angle. Ask them if they see an "L". Repeat several times.

Now give the students a bag of different size marbles and string and let them

try to see what kinds of angles are made when you hit two marbles together.

Have them observe if the angle changes when the marbles are the same compared to

when the marbles are different. Discuss the observations with the class.Performance Assessment:

Students should be able to describe what "transfer" means, when discussing

transfer of momentum.