A 60-kg box is being pushed a distance of 6.2 m across the floor by a force P with arrow whose magnitude is 150 N. The force P with arrow is parallel to the displacement of the box. The coefficient of kinetic friction is 0.21. Determine the work done on the box by each of the four forces that act on the box. Be sure to include the proper plus or minus sign for the work done by each force. (The floor is level and horizontal. Forces that act on the box: pushing force P, frictional force f, normal force N, and weight mg.)

Explanation:

mass of box, m = 60 kg

distance, d = 6.2 m

force, P = 150 N

coefficient of kinetic friction, μk = 0.21

work done by the gravitational force, Wg = Force x distance x cos 90

Wg = 0 J

Work done by the normal force, Wn = force x distance x Cos 90

Wn = 0 J

Work done by the friction force, Wf = - μk mg d

Wf = - 0.21 x 60 x 9.8 x 6.2 = - 765.58 J

Work done by the applied force, Wp = P x d

Wp = 150 x 6.2 = 930 J

freezing

deposition

condensation

explanation;

melting also called fusion is the process where solid becomes liquid, sublimation is the process where solid becomes gaseous without first changing to liquid, deposition involves change from gaseous to solid state, freezing involves change from liquid to solid, boiling or evaporation involves change of liquid to gaseous state, while condensation is the change from gaseous state to liquid state.

endothermic reactions involves absorption of heat from the surroundings or the environment while exothermic reactions involves loss of heat energy to the surroundings.

in this case, sublimation, evaporation and melting are endothermic reactions (gain energy from the environment) while, freezing, deposition and condensation are exothermic (loss of energy to the surroundings) reactions.

graphing motion: mastery test

209be

what is the instantaneous acceleration of

the particle at point b?

0 meters/second?

10 meters/second?

12 meters/second?

velocity imetersisecond

15 meters/second?

20

time (seconds)

answer: 0 meters/second^2