1) A moving cart is given a push by someone’s hand so that a force is exerted on it. The force diagram for a moment in time while this force is acting is shown here.

  
 
 

Several seconds later it is observed that the cart is still moving, but measurements show that the force of the hand is no longer acting on the cart. Which of the force diagrams below would be most appropriate for the cart at this later moment in time?

Force diagram A

Force diagram B

Force diagram C

2) A child’s sled is sliding across a frozen lake toward a patch of thin ice. To try and prevent this, you lasso the sled and pull on the rope in the opposite direction to its motion to try and slow it down. Which of the diagrams below would best represent this situation, assuming it is for a moment in time before you successfully brought the sled to a stop?

Force diagram A

Force diagram B

Force diagram C

3) While arguing over who owns a toy, two children, Cindy and Scott, both grab it and engage in a ‘tug-of-war’ over it. At one certain moment in time during their struggle, the force diagram for the toy looks like this.

Which of the following statements best describes what this force diagram represents?

Scott is pulling harder than Cindy, and the toy is moving toward him at this particular moment in time.

Cindy is pulling harder than Scott, and the toy is moving toward her at this particular moment in time.

Cindy is not pulling as hard as Scott, but the toy is moving toward her at this particular moment in time.

At this particular moment in time Scott and Cindy are pulling equally hard, so the toy is not moving.

4) Here are the force diagrams for two carts being pushed forward as they move along separate tracks.

Which of these two carts is moving faster?
 

 

Force exerted on cart by hand