What is the basic unit for length

A spaceship is built to reach a star system 15 light-years away. (a) How fast must the spaceship move (in units of c) so that the round trip time experienced by the crew is 20 years?

A bus travels 20 KM and 30 minutes what is average speed of the bus

A 15.0-kg block is dragged over a rough, horizontal surface by a 75-n force acting at 21° above the horizontal. the block is displaced 5.7 m, and the coefficient of kinetic friction is 0.200. (a) find the work done on the block by the 75-n force.

A boy jumps on his bed when his feet push the bed down what is the reaction force

The moon's gravity is one-sixth that of the earth. What is the period of a 0.25m long pendulum on the moon?

What happens when light from the Sun passes through any type of matter?

A balanced chemical reaction obeys the law of

5. If you push a chair across the floor at a constant velocity, how does the force of friction compare with the force you exert? Explain.

if a parachute and a stone is dropped from a certain height at once on the Moon which will reach the surface of moon

While goofing off at the ice skating rink, a student takes off her shoes and places each of them on the ice. Her friend, a hockey player, then shoots a hockey puck at each shoe.