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2. An object is suspended from a spring scale in an elevator. The reading of the scale is 200 N when the elevator is at rest. If the balance reading is 190 N, the elevator is moving a. down and increasing in speed. b. down and decreasing in speed. c. up at constant speed. d. down at constant speed. 3. A 92.0 kg baseball player slides into second base. The coefficient of friction between the player and the ground is 0.61. What is the magnitude of the friction force? Round your answer to the nearest whole number and include units. 4.A boy is pushing a 60 kg box along the floor by applying a horizontal force of 150 N. The box is accelerating at a rate of 0.5 m/s2. What is the coefficient of kinetic friction between the box and the floor? Round your answer to two decimal places. 6. A 1250 kilogram car skids to a stop from a speed of 35 m/s in 4.5 s. What is the coefficient of kinetic friction (uk) between the tires and the road? Round your answer to two digits. 8. The force of friction: a. acts only when an object is in motion b. acts equal and opposite to any net force on the object c. acts parallel to the surface d. a and b are correct e. b and c are correct f. a, b, and c are correct 9. An astronaut picks up a stone on the moon and finds its mass to be 2 kg. If the acceleration of gravity on the earth is 6 times more than on the moon, what will the mass and the weight of the stone be on the earth? a. 2.0 kg / 19.6 N b. 11.8 kg / 115.6 N c. 19.6 kg / 192.1 N d. 2.0 kg / 12.0 N 10.A 3000 kg truck starts from rest and rolls down a hill with constant acceleration. It travels a distance of 400.0 m in the first 25.0 s. Calculate the magnitude of the net force on the truck