Which of the following is considered a physical change?

A:burning paper

B:rusting of metal

C:evaporating water

Two spacemen are floating together with zero speed in a gravity-free region of space. The mass of spaceman A is 140 kg and that of spaceman B is 100 kg. Spaceman A pushes B away from him with B attaining a final speed of 0.5 m/s.

Why can some 1.5 volt batteries be recharged and used over and over again?

all of the following require breaking informing chemical bonds except lighting a campfire breaking a rock baking a potato rotting fruit

A roller coaster takes energy to make the first rise, but then it should be able to run the course of the track without any input of energy. This, however, is not true. Energy continues to be needed.

One advantage of a fever is that it can slow down the

N object moves in a circular path at a constant speed. what is the relationship between the directions of the object's velocity and acceleration vectors?

Explain what force caused the continents to move from one super continent to there current form

A 5 kg ball approaches a wall at a speed of 4 m/s. It then bounces off the wall in the opposite direction at the same speed. What is the magnitude of the average force exerted on the ball if it is in contact with the wall for 0.1 s?

When a basketball player dribbles a ball, it falls to the floor and bounces up. Is a force required to make it bounce? Why? If a force is needed, what is the agent involved?

Compare the friction force on the cart when it is rolling along the blacktop parking lot to the friction force on the cart when it is inside the grocery store (assume the flooring is smooth vinyl tile).