An object's motion changes
A. when there are no forces acting upon it.
B. only when a nonzero net force is applied to the object.
C. when the forces acting on the object remain balanced.
D. only if the object is at rest when a force acts upon it.

Ahypothesis is? close agreement by competent observers of observations of the same phenomena. a guess that has been tested over and over again and always found to be true. an educated guess that has yet to be proven by experiment. the long side of a right triangle. a synthesis of a large collection of information that includes guesses.

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final

Holes drilled several kilometers into earth’s crust provide direct evidence about earth’s interior in the form of