All engines operate at less than 100 percent efficiency because they

A. absorb heat

B. conduct heat

C. burn gasoline

D. emit heat

What do you call the curved upper surface of the water that comely appears when using a graduated cylinder

If you push on a wall with a force of 200 N, with what force does the wall push back?

How do birds manage to fly without flapping their wings?

Problem 3: Thermal expansionThe steel rod has the length 2 m and cross-section area 200 cm2at the room temperature 20◦C. Weapply the heat source and the temperature of the rod increases. The coefficient of linear expansion isα = 2*10-6K-1.

An egg is dropped from a height of 20 m. The egg is in free fall the entire time it falls. What wilLthe speed of the egg be when it lands after fallinG for 2 seconds?

Two objects have the same momentum. Do the velocities of these objects necessarily have (a) the same directions and (b) the same magnitudes? Give your reasoning in each case.

If you keep voltage constant and increase resistance resistance, what happens to current?

A scene in a movie has a stuntman falling through a floor onto a bed in the room below. The plan is to have the actor fall on his back, but a researcher has been hired to investigate the safety of this stunt.

During energy transformation, all energy systems: are a. 100 percent efficient b. lose energy c. gain heat energy d. create energy

An apple with a mass of 0.95 kilograms hangs from 3.0 meters above the ground. What is the potential energy of the apple