3. Shown is the block m=5 kg. Coefficients of static and kinetic friction are 0.3 and 0.1, respectively. a) What magnitude of force F will set the block in motion? b) After system starts moving, what is the acceleration of the block? Use 2nd Newton's Law. Be careful when calculating normal force, it's not mg! 20°

A robot pushes a 20-kg box on the horizontal surface as part of the moving job, the force is 35 N to the left shown. The box does not move. The coefficients of friction between the floor and box are µs = 0.75 and µk = 0.40. Use g = 10 m/s². Match the anwers with questions. (Hint: Draw a proper free-body diagram.) ◆ What is the magnitude and direction of the pushing force on the box from the hand? What is the magnitude and direction of the weight force on the box from the earth? ◆ What is the magnitude and direction of the normal force on the box from the floor? A A What is the magnitude and direction of the friction force on the box from the floor? What is the net force on the box? A. 200 N, to the left B. 200 N, down C. zero, therefore no direction D. 35 N, down E. 35 N, to the left F. none of the given G. 35 N, to the right H. 200 N, up 1. 35 N, up J. 200 N, to the right

18. A child sits on a sled at the top of a hill, the hill makes an angle of 20° with the horizontal. The child's mass is 40kg. Use us = .1 and 4.03 a. b. Draw a free body diagram for this system. Does the child accelerate down the hill? *i.e., check that the coefficient of static friction is vercome by the component of the childs weight in the direction the child would accelerate. If they do, what is their acceleration? *use coefficient of kinetic friction in sum of the forces balance if the child moves.

1) The block on a 60° inclined plane weighs 100 pound and is held by the minimum possible force T as shown in the figure. The coefficient of both static and kinetic friction between the block and the inclined plane is 0.2, and the pulleys are frictionless. T а. Draw the free body diagram (FBD) of the block showing all forces and their directions acting on it. b. Compute all unknown forces including T shown in your FBD. Now if you want to move the block upward on the inclined plane С. by applying minimum possible force T then draw the FBD of the block showing all forces with directions acting on it. d. Now assume the pulleys are stuck (do not rotate any more) and the 60° rope slides over the stuck pulleys as the block moves up. the coefficient of both static and kinetic friction between the pulley surface and the rope is 0.1. Draw the FBD of the block showing all forces with directions acting on the block when the block is pulled upward by the minimum rope force T. е. For the stuck…