Answer the multiple-choice below.

1. A small block slides without friction along a track toward a circular loop. The block has more than enough speed to remain firmly in contact with the track as it goes around the loop. The magnitude of the block's acceleration at the bottom of the loop is a) Greater than zero but less than g. b) Zero. c) Equal to g d) Greater than g

2. A vehicle lands on Mars and explores its surface. The average gravitational field on the surface of Mars is 3.7 N kg. The weight of the vehicle is defined as the gravitational force exerted on it. Which of the following statements are true about the vehicle's weight? Select two answers.

a) the vehicle's weight was constant until it reached the surface of Mars.

b) the vehicle's weight increased while it was descending to the surface of Mars.

c) the vehicle's weight always equals the normal force exerted by mars on the vehicle while it is landing.

d) the vehicle weighs less on the surface of Mars than on the surface of the earth.