A student slides her 80.0-kg desk across the level floor of her dormitory room a distance 4.00 m at constant speed. If the coefficient of kinetic friction between the desk and the floor is 0.400, how much work did she do?
A) 128 J
B) 3.14 kJ
C) 26.7 J
D) 1.26 kJ
E) 24.0 J
D
You might also like to view...
Two forces of magnitude 50 N, as shown in the figure below, act on a cylinder of radius 4 m and mass 6.25 kg. The cylinder, which is initially at rest, sits on a frictionless surface. After 1 second, the velocity and angular velocity of the cylinder in m/s and rad/s are respectively
A. v = 0; ? = 0. B. v = 0; ? = 4. C. v = 0; ? = 8. D. v = 8; ? = 8. E. v = 16; ? = 8.
A uniform meter stick is freely pivoted about the 0.20-m mark. If it is allowed to swing in a vertical plane with a small amplitude and friction, what is the frequency of its oscillations?
A) 0.55 Hz B) 0.66 Hz C) 0.92 Hz D) 1.1 Hz E) 1.3 Hz
Two speakers are placed side by side and driven by the same frequency of 0.50 kHz
If the distance from a person to one speaker is 5.0 m and the person detects little or no sound, which of the following is a possible the distance from the person to the other speaker? The sound speed in the room is 340 m/s. A) 7.7 m B) 8.1 m C) 8.4 m D) 9.1 m
Two objects, one less massive than the other, collide elastically and bounce back after the collision. If the two originally had velocities that were equal in size but opposite in direction, then which one will be moving slower after the collision?
a. The less massive one. b. The more massive one. c. The speeds will be the same after the collision. d. There is no way to be sure without the actual masses.