1. Look at the blue lines coming from the fan. In which direction is the air pushed?
2.Press Play ( ) and observe the cart. In which direction does the cart move?
3.The velocity (v) of the cart is its speed and direction. Click Reset ( ). Select the BAR
CHART tab, and click Play. Does the velocity change or stay the same
Question: What happens to the cart when there is no force?
1. Form hypothesis: What will the motion of the cart be like when there is no force at
2.Predict: Suppose a cart with no fans has a starting velocity of 2 m/s. What will be the
velocity of the cart when it reaches the wall?
3. Experiment: Check that there are no fans on the cart. On the DESCRIPTION tab, set
the Initial velocity of cart to 2.0 m/s. Select the BAR CHART tab, and click Play. What do
you notice about the velocity of the cart?
4. Experiment: Click Reset. Place two fans on the cart, and point them in opposite
directions. (Next to DIRECTION, click the button for one fan.) Turn both fans on, and
click Play. What do you notice about the velocity of the cart