A heat engine has a temperature of 1800 K. Some of the heat from the engine flows to the surroundings, which are at a temperature of 160 K. What is the approximate efficiency of the engine? A. 16%
B. 91%
C. 103%
D. 109%

An electric current is flowing through the cord below.what will happen to this current if a magnet is brought near the cord? a. the electric current will stop flowing. b. it will exert a force on the voltage. c. the resistance of the wire will decrease. d. it will exert a force on the electric current.

Alfred pushes on a heavy box, but cannot move it. the box has a lot of inertia motion friction gravity

Clothes dryer uses about 7 amps of current from a 240 volt line. how much power does it use?