A mechanical device requires 420 J of work to do 230 J of work to lift a crate. What is the efficiency of the device? 190% 0.5% 183% 55%

What are the two ways a person feels weightless?

How does the current in a resistor change if the voltage across the resistor is decreased by 4

Green light has a lower frequency than blue light. Which color of light has a longer wavelength?

What two models are used to describe how light behaves

Which topic in a biology textbook is directly related to physics?

Suppose your hair grows at the rate of 1/55 inch per day. Find the rate at which it grows in nanometers per second. Because the distance between atoms in a molecule is on the order of 0.

A water skier is pulled behind a boat. When the skis push down on the water, what is the reaction force? A. The skier pulls back on the boat. B. Earth's gravity pulls down on the skis. C. The water pushes up on the skis. D. The boat pulls the skier.

Approximately how much electrical energy does a 5-W light bulb convert to radiant or thermal energy in one hour

If a clock expends 2 W of power from a 1.5 V battery what amount of current is supplying the clock?

The rectangular plates in a parallel-plate capacitor are 0.063 m * 5.4 m. A distance of 3.5 * 10-5 m separates the plates. The plates are separated by a dielectric made of Teflon, which has a dielectric constant of 2.1.