500 J of work are done in 4 seconds to lift a 40 kg box to the top of a high shelf. How much power was required to complete the lift?

A very hot gas made of particles with an electric charge is a?

Which planet is covered with red, iron-oxide dust? A. Mercury B. Venus C. Earth D. Mars

a man drops a ball downside from the roof of a tower of height 400 meters. At the same time another ball is thrown upside with a velocity 50 m/s from the surface of the tower, find when and at which height from the surface of the tower the two balls

Which of the following describes density only in terms of metric units? a. kilograms per cubic meter b. pounds per square meter c. pounds per cubic foot d. grams per cubic foot

Atoms of elements in the same group have the same number of [Blank] This is why they have similar chemical properties. A. Protons B. neutrons C. Valence electrons

When the velocity of a mass on a spring is zero, the acceleration is at

Which is a disadvantage of using wind as an energy source? Check all that apply. It may be unreliable. It is not naturally occurring. It produces a lot of waste. It requires wires to carry electricity. It generates large amounts of electricity.

One step in the production of hydroelectric power involves

A pot is heated on a stove. The water begins to boil rabidly. Which explains why the water is boiling fast?

A galvanometer can be calibrated to read electric A) current B) Voltage C) either of these D) neither of these