Fuel cells are devices that

A. directly convert hydrogen to electricity.

B. store solar energy.

C. spin turbines.

A 1200 kg car is brought from 25 m/s to 10m/s over a time period of 5 seconds. Determine the force experienced by the car

What is the speed of light in a vacuum

The meeting in orbit of two or more spacecraft is A. orbital countermand. B. orbital farce. C. orbital hit. D. orbital rendezvous.

A helical gear has 30 teeth and a pitch diameter of 280 mm. Gear module is 8 and pressure angle normal to tooth is 20°. The force normal to the tooth surface is 4500 N. Determine the kW transmitted at 620 rpm.

When a simple machine multiplies force, it decreases a. potential energy. b. distance moved. c. both d. neither?

How does the sun's heat affect the humidity of a place

Which "spheres" are interacting when water evaporates from plants

Which of Einstein's theories was most important?

Which of these statements best describes a similarity between the two galaxies? Both have elongated centers. Both have centers shaped like bars. Both change their shape from time to time. Both are held together by gravitational forces.

The part of the earth system that includes earths solid, rocky, outer layer is the