1) The force of gravity

a) is an attractive force only

b) is a repulsive force only

c) can be attractive or repulsive

d) is neither an attractive or repulsive force

2) as the distance from the surface of the earth increases, the force of gravity

a) increases

b) decreases

c) stays the same

d) may increase or decrease depending on the situation

3) Two objects are experiencing a force of gravitational attraction. If you triple the mass of one of the objects and double the distance between their centres, the new force of gravity compared to the old (Fg) will be:

a) 3 Fg

b) 1.5 Fg

c) 0.75 Fg

d) the same

4) Two mountains are 1.00 km apart. If their masses are identical (2.00 10^10 kg), what is the force due to gravity between the mountains?

a) 2.67 x 10^4 N

b) 1.33 x 10^ -6 N

c) 2.67 x 10^7 N

d) 2.67 x 10^ 10 N

5) The moon's period of revolution around the Earth is 27.3 d. How far away is the moon?

a)1.33 x 10^7 km b) 3.83 x 10^5 km

c) 3.77 x 10^ 8 km

d) 4.88 x 10^ 9 km