1) Choose the correct answer

a) What prevents Earth and the Moon from being an isolated system?

i) the gravitational attraction of Pluto

ii) the gravitational attraction of the sun

iii) all of the options

iv) the gravitational attraction of Saturn

b) Suppose two billiard balls, A and B, with the same mass undergo a head-on elastic collision. Ball A was initially stationary. Which of the following outcomes is possible following the collision?

i) one ball is moving and one is stationary

ii) both balls are stationary

iii) all of the outcomes are possible

iv) both balls are moving

c) Suppose object A has greater momentum than object B. Which of the following can you conclude?

i) none of the options are necessarily true

ii) object A has a greater velocity than object B

iii) object A has a greater mass than object B

iv) object A has a greater kinetic energy than object B