Your friend Nader is standing 400,000 meters away. If you send a message to him using radio waves, how long will it take for him to receive it? Round to four decimal places.

To compress spring 1 by 0.20m takes 150j of work. stretching spring by 2 by 0.30 m requires 210j of work. which spring is stiffer?

What is the initial speed of water if it rises to the height of 171m

What is 20.0 m/s for 10 mi

A very famous scientist explains a recently observed natural phenomenon with a new theory. Should the new theory be considered valid?

Alicia can row 6 miles downstream in the same time it takes her to row 4 miles upstream. She rows downstream 3 miles/hour faster than she rows upstream. Find Alicia's rowing rate each way. Round your answers to the nearest tenth, if necessary.

Imagine that you replace the block in the video with a happy or sad ball identical to the one used as a pendulum, so that the sad ball strikes a sad ball and the happy ball strikes a happy ball.

Under what conditions will an object experience a gravitational force? Under what conditions will an object experience an electric force? Under what conditions will an object experience a magnetic force?

A basketball player pushes down with a force of 34 N on a basketball that is inflated to a gauge pressure of 9 x 104 Pa. What is the diameter of contact between the ball! and the floor?

Match these terms with their definitions: 1. unit of electrical resistance ampere 2. unit of electromotive force or electrical potential ohm 3. unit for measuring the strength of an electric current volt 4. unit of electrical power watt

In which is momentum conserved: an elastic collision or an inelastic collision?