Author Question: A person gives a shopping cart an initial push along a horizontal floor to get it moving, and then ... (Read 191 times)

krzymel · **on:** Jul 29, 2018

A person gives a shopping cart an initial push along a horizontal floor to get it moving, and then lets go. The cart travels forward along the floor, gradually slowing as it moves.

Consider the horizontal force(s) on the cart while it is moving forward and slowing. Which of the following statements is correct? A) Both a forward and a backward force are acting on the cart, but the forward force is larger.
B) Both a forward and a backward force are acting on the cart, but the backward force is larger.
C) Only a forward force is acting which diminishes with time.
D) Only a backward force is acting, no forward force.

Question 2

The electric field between square the plates of a parallel-plate capacitor has magnitude E.

The potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. The magnitude of the electric field between the plates is now equal to
A) E/2. B) 2E. C) E/4. D) E. E) 4E.