A 10-N toy rocket blasts straight up from ground level with an initial kinetic energy of 40 J. At the exact top of its trajectory, the total mechanical energy of the rocket-Earth system is 140 J.
To what vertical height above the ground does it rise, assuming no air resistance? A) 1.0 m
B) 10 m
C) 14 m
D) 24 m
Question 2
One way of stating the principle of relativity is:
A) Light has the same speed for all nonaccelerated observers.
B) Experiments conducted entirely within your own lab will come out differently, depending on the state of motion of the lab relative to other reference frames.
C) Observers that are accelerated will see light beams move at something other than lightspeed.
D) Unless you look outside, you cannot tell how fast you are going.
E) The speed of light is relative to the motion of the observer, provided that the observer is not accelerated.