Physics MCQS
1. Which of the following is NOT a correct unit for work? A. erg B. ft·lb C. watt D. newton·meter E. joule ans: C 2. Which of the following groups does NOT contain a scalar quantity? A. velocity, force, power B. displacement, acceleration, force C. acceleration, speed, work D. energy, work, distance E. pressure, weight, time ans: B 3. A boy holds a 40-N weight at arm’s length for 10 s. His arm is 1.5 m above the ground. The work done by the force of the boy on the weight while he is holding it is: A. 0 B. 6.1 J C. 40 J D. 60 J E. 90 J ans: A 4. An object moves in a circle at constant speed. The work done by the centripetal force is zero because: A. the displacement for each revolution is zero B. the average force for each revolution is zero C. there is no friction D. the magnitude of the acceleration is zero E. the centripetal force is perpendicular to the velocity ans: E 5. An object of mass 1 g is whirled in a horizontal ci