Correct answer is given, please explain why for each.

Concept Question 1 – A rock is thrown straight up from thesurface of the earth. Ignoring air resistance, which of thefollowing statements is correct as the rock moves upward? a) Thetotal energy of the rock increases. b) Both the kinetic energy andthe gravitational potential energy of the rock remain the same. c)Both the gravitational potential energy and the total energy of therock increase. d) Both the kinetic energy and the total energy ofthe rock decrease. e) The kinetic energy of the rock decreases andthe gravitational potential energy of the rock increases.

E is correct.

Concept Question 2 – A stationary bomb explodes in spacebreaking into several fragments. The net external force on the bombat the time of the explosion is zero. Which statement is correct?a) The total kinetic energy is conserved. b) The sum of the kineticenergies of all the fragments is zero. c) The vector sum of thelinear momenta of the fragments is zero. d) The velocity of any onefragment must be equal to the velocity of any other fragment. e)The speed of any one fragment must be equal to the speed of anyother fragment.

C is correct

Concept Question 3 – Complete the statement: A collision iselastic if a) the total final momentum of the system is zero. b)the objects stick together. c) the final kinetic energy of thesystem is zero. d) the total kinetic energy of the system isconserved. e) the total momentum of the system is conserved.

D is correct.