(D) 5.0 N
(E) 3.3 N
4 . The velocity–time graph above represents the motion of a 5-kg box. The only force applied to this box
is a person pushing. Assuming that the box is moving to the right, what is the magnitude and direction
of the force applied by the person pushing?
(A) 2.0 N, right
(B) 2.0 N, left
(C) 0.4 N, right
(D) 0.4 N, left
(E) 12.5 N, left
Free Response:
5 . A 2-kg block and a 5-kg block are connected as shown above. The coefficient of friction between the
5-kg block and the flat surface is θ = 0.2.
(A) Calculate the magnitude of the acceleration of the 5-kg block.
(B) Calculate the tension in the rope connecting the two blocks.
6 . Bert, Ernie, and Oscar are discussing the gas mileage of cars. Specifically, they are wondering
whether a car gets better mileage on a city street or on a freeway. All agree (correctly) that the gas
mileage of a car depends on the force that is produced by the car’s engine—the car gets fewer miles
per gallon if the engine must produce more force. Whose explanation is completely correct?
Bert says: Gas mileage is better on the freeway. In town the car is always speeding up and slowing
