Which is not a characteristic of a heat pump? a. it is used in air conditioners. b. it uses a refrigerant. c. it requires no work. d. it reverses the normal flow of thermal energy.

Abaseball picther can throw a ball at about 90 miles per hour, v = 40 m/s, on solid rock ground. we now put him into space. when he throws the ball, which weighs mb = 0.15 kg moves away from himat the same speed. how long does it take the ball thrown in space to travel the 30 meters to the batter? he weighs mp = 100kg

Properties seen when one one substance changes to another are known as properties

Consider two regions of space containing a static electric field, region a and region b. in region a the equipotential lines are more closely spaced than those in region b. what can be said about the relative strength of the electric field in the two regions? a) the electric field in region a is stronger th