Where we see that there are obvious changes in the velocity at various times. We are interested in understand what causes these changes in velocity.

The fan attachment exerts an almost constant force on the cart. What is the relationship between that strength of that force and the cart's acceleration?

Possible hypothesis

• Acceleration depends on the total force. More force, more acceleration?
• Acceleration only depends on the initial force (the impulse) and not on a continuous force. Initial acceleration to constant velocity or constant acceleration?
• Acceleration depends on mass. More mass, more acceleration?
• Acceleration is inversely proportional to the mass. More mass, less acceleration?

Question to think about: Does the relationship between force, mass and acceleration by itself predict that objects of different mass will fall at the same rate in the earth's gravitational field?