A student pushes a 40-N block across the floor for a distance of 10 m. How much work was applied to move the block?

A.

4 J

B.

40 J

C.

400 J

D.

4000 J

Freezing and melting are two different physical changes that involve the same amount of energy. Compare and contrast the potential energy diagrams that would represent each of these processes. Be specific in your comparison.

Very light items remain on the surface of water because of surface currents. True or false

Y = - 2x + 5 and 2x + y = - 7

An ionic compound is a compound that consists of molecules made of atoms that are covalently bonded. True or False?

Which process requires more energy: completely vaporizing 1 kg of saturated liquid water at 1 atm pressure or completely vaporizing 1 kg of saturated liquid water at 8 atm pressure?

A small kid sits on a bike (Anita). A bigger and stronger person (Jamy) pushing the kid so that the kid starts speeding up. (neglect friction). Mark all correct statements about the forces between them. A.

A ___ is awarded to the opposing team when that team violently or dangerously charges a opponent. (in soccer) A) Goalie kick B) Indirect kick C) Direct kick D) Throw in

Which has greater potential energy, a book on the top shelf of a bookcase or a book on the bottom shelf? Why?

Fusion occurs with atoms of elements less massive than a. iron. b. helium. c. calcium. d. uranium.

Which describes what happens when fuel is ignited in a heat engine? A. Chemical energy is converted into thermal energy B. Thermal energy is converted into solar energy. C. Solar energy is converted into chemical energy D.