If everything with mass is attracted to every other thing with mass, why doesn’t all the matter in the universe pull together in a giant ball of stuff?

Imagine that someone pushes one marble toward a motionless marble. would there still be action-reaction forces involved in the collision? how might the marbles’ motions be changed? ?

In a system with only a single force acting upon a body, what is the relationship between the change in kinetic energy and the work done by the force? answers: work is equal to the change in kinetic energy. work depends on the square of the change in potential energy. work is equal to the negative of the change in kinetic energy. work is equal to the square of the change in kinetic energy

As microwave light travels through a liquid, it moves at a speed of 2.2 x 108 m/s. if the frequency of this light wave is 1.1 x 108 hz, what is the wavelength of this microwave?