Jim releases a compressed spring. describe the energy transformation taking place in the spring.

a potential energy to kinetic energy, and total energy is conserved b kinetic energy to potential energy, and some energy is lost as heat c kinetic energy to potential energy, and potential energy is equal to kinetic energy d potential energy to kinetic energy, and potential energy is always greater than kinetic energy

This is the answer: body 1 + engine 2

Answertraveling around a circular trackexplanation"traveling around a circular track" is the best answer as you could be traveling around a circular track at a constant speed. your velocity would therefore have the same magnitude but will always be constantly direction. since acceleration is the rate of change of velocity, the rate of change will only involve the direction of velocity and not the magnitude.wrong choices: "an object at rest" does not accelerate at all"increasing speed while traveling around a curve" means that the acceleration will not be constant due to only change in direction; it will be constant due to both magnitude and direction"an object in free fall" does not necessarily change direction 

Actually the earth is this question makes no sense