Answer to Question #275310 in Classical Mechanics for hjdshsdhkdh2

Question

An object has a positive velocity and a decreasing kinetic energy, which of the following could apply to this situation?

(a) It has a positive position moving toward the origin under a negative net force.

(b) It has a negative position moving away from the origin under a negative net force.

(c) It has a negative position moving toward the origin with a positive acceleration.

(d) It has a positive position moving away from the origin and speeding up.

(e) It has a negative position moving toward the origin and slowing down.

Which of the following is ALWAYS true?

(a) An object with a positive net force acting on it has an increasing kinetic energy.

(b) An object with a constant non-zero net force has a changing kinetic energy.

(c) If an object has a constant kinetic energy, its velocity is also constant.

(d) If an object has a constant kinetic energy the net force acting on it is zero.

(e) If an object's kinetic energy is constant, then the object's acceleration is zero.

Answer 1

An object has a positive velocity and a decreasing kinetic energy, which means that it has a negative position moving toward the origin and slowing down.

The following is ALWAYS true: If an object has a constant kinetic energy, the net force acting on it is zero.