Which elements do hydrogen fuel cells combine to produce electricty

Suppose a ball has a potential energy of 5 J when you drop it. What would be its kinetic energy just as it hit the ground? (Ignore the effect of air resistance.)

If planet A is four times as far from the sun as planet C, then the period of its orbit will be__ times as long

A 0.140 kg baseball is thrown horizontally with a velocity of 28.9 m/s. It is struck with a constant horizontal force that lasts for 1.85 ms, which results in a velocity of 37.0 m/s in the opposite direction.

The technician said that the machine is sanitizing properly when the iodine sanitizer turns the color of the paper because the concentration is

A gas is confined to a cylinder under constant atmospheric pressure, as illustrated in the following figure. When the gas undergoes a particular chemical reaction, it absorbs 829J of heat from its surroundings and has 0.

1) How is chemical energy transformed into potential energy?

A double-paned window has two glass panes separated by a layer of air. Why is air, rather than glass, used to fill this space?

To determine waves frequency you must know the what

What is the average speed in miles per hour of the car that traveled a total of 200 miles in 5.5 hours

A solid weighs 277.5 g in air and 212.5 g when totally immersed in the liquid of density 0.9 g / cc. Calculate the density of the solid.