A 42 kg is lifted to a height of 9 m. What is the gravitational potential energy?

A rock of mass 7 kg is being whirled in a horizontal circle on the end of a rope 2.5m long. if the tangential speed of the rock is 2.3m/s, what is the tension in the rope?

A magnetic hockey puck (0.40 kg) hits another hockey puck (0.40 kg) at rest and both travel together to the right at 8.0 m/s. How fast was the first hockey puck initially moving?

The universe contains billions of galaxies. The largest galaxies contain a trillion stars. What holds each galaxy together?

Two objects attract each other gravitationally. If the distance between their centers increases by a factor of 3, and both of the objects' masses increase by the same factor, how does the gravitational force between them change?

Which statement correctly compares infrared light to ultraviolet light A. Infrared light has a lower frequency and shorter wavelength than ultraviolet light B.

Two masses are separated by 1 m. suppose the masses are moved so they are 2 m apart how will the gravitational force change

Bob rubs a piece of fur on a hand rubber rod, giving the rod a negative charge. what happens?

The period of a simple pendulum is 3.8 s. the length of the pendulum is doubled. what is the period t of the longer pendulum? t = s

True or false - sound waves can travel across outer space.

In which one of the following locations can a person hear the echo of a sound? a. At least 33.2 meters behind the reflecting surface b. Less than 16.6 meters in front of the reflecting surface c. Less than 33.2 meters behind the reflecting surface d.