While standing in a low tunnel, you raise your arms and push against the ceiling with a force of 100 N. Your mass is 70 kg. a. What force does the ceiling exert on you? A. 10 N           B. 100 N            C. 690 N D. 790 N         E. 980 N b. What force does the floor exert on you? A. 10 N            B. 100 N        C. 690 N D. 790 N          E. 980 N

8. 45 kg skier slides down a 410 incline. What would be the magnitude of the skier's acceleration if friction is ignored? A. 2.5 m/s2 O B. 1.65 m/s2 C. 0.4 m/s2 O D. 6.4 m/s2 O E. 0.6 m/s2 O F. 5 m/s2 G. zero

A soccer player kicks a rock horizontally off a 40.0-m high cliff into a pool of water. If the player hears the sound of the splash 3.00 s later, what was the initial speed given to the rock? Assume the speed of sound in air to be 343 m/s.

65.0 N 30 30.0 N- 20 20.0 N What is the magnitude of the resultant of these three forces? a. 27.0 N b. 33.2 N c. 36.3 N d. 23.8 N 105 N e.

A. 700 N 100 N Dick and Jane stand on a platform of negligible weight, as shown in the figure. Dick weighs 700 N, and Jane weighs 400 N. Jane is pulling down on the rope creating tension in it and supporting some of her weight. Assume the platform is in _equilibrium approximately what is the downward force that Jane is exerting on the platform? ON B. C 370 N D. E. 50 N DICK 33 N JANE 400 N

15. A 100kg wooden box is placed in an inclined ramp with angle of inclination equal to 40 degrees. What is the normal force exerted by the inclined ramp on the box? *     A. 712N B. 732N C. 751N D. 767N E. 787N   16. Find the force that makes the box slide down the ramp in #15 above. *   A. 615N B.630N C. 645N D. 660N E. 675N

A 4.10-kg block is at rest on a horizontal floor. If you push horizontally on the 4.10-kg block with a force of 12.0 N, it just starts to move. a. What is the coefficient of static friction? b. A 7.00-kg block is stacked on top of the 4.10-kg block. What is the magnitude F of the force, acting horizontally on the 4.10-kg block as before, that is required to make the two blocks start to move together? answer in N

U04

44. A 6.0 N force is applied to box 1, which is in contact with box 2 on a frictionless surface as shown below. What force does box 1 exert on box 2?A. 2.0 NB. 3.0 NC. 4.0 ND. 6.0 N

A 200 kg object stay in rest on a 60 degree slope, the normal force on the object is: a. 200 kg b. 1960 N c. 1697 N d. 490 N e. 980 N