S$3$: Shown to the right are speed$-$

time graphs for two carts that

were involved in a collision

similar to what you observed

in Experiment $2$ of this activity.

$($To remind you, you gave the

"launched cart" a quick push

and it then collided with a

stationary "target cart."$)$ In

this case students used two

Motion Sensors and recorded

the speed of both carts over

the same period of time.

On the graphs, use a colored

pencil to indicate:

a$)$ the period over which you

think the hand was in contact

with the launched cart.

b$)$ the period on both graphs over

which you think the two carts

were in contact.