In order for work to take place

A runaway railroad car, with mass 4.50 * 105 kg, coasts across a level track at 3.80 m/s when it collides with a spring-loaded bumper at the end of the track. If the spring constant of the bumper is 3.

Special relativity can be used to study an object in which frame of reference? A. A frame of reference that is moving at a constant velocity B. A frame of reference that is speeding up C. A frame of reference that is moving in a circle D.

What is area and perimeter

Last night my family ordered pizza for dinner. when I finished I threw the 300g box across the floor at 2m/s. the floor has 0.3mu. how far did the box go?

A solenoid 10.0 cm in diameter and 75.0 cm long is made from copper wire of diameter 0.100 cm, with very thin insulation. The wire is wound onto a cardboard tube in a single layer, with adja - cent turns touching each other.

A geologist estimates that a large boulder weighs 7840 N. What should he estimate the mass of this boulder to be? A. 650 kg B. 740 kg C. 780 kg D. 800 kg

Two objects have the same momentum. Do the velocities of these objects necessarily have (a) the same directions and (b) the same magnitudes? Give your reasoning in each case.

If you keep voltage constant and increase resistance resistance, what happens to current?

A scene in a movie has a stuntman falling through a floor onto a bed in the room below. The plan is to have the actor fall on his back, but a researcher has been hired to investigate the safety of this stunt.

During energy transformation, all energy systems: are a. 100 percent efficient b. lose energy c. gain heat energy d. create energy