Problem 4: Shown to the right is a block of mass m = 12.8 kg sitting on a ramp that makes an angle 0 = 21° with the horizontal. This block is being pushed by a horizontal force F = 240 N. The coefficient of kinetic friction between the two surfaces is u = 0.43. m

You are a bully.  You pin a 48 kg dweeb to a wall so that his feet aren't touching the ground.  Your arm is extended so that it makes an angle 28 degrees with the horizontal.  The dweeb's back is so sweaty with fear that there is no friction between his back and the wall.  What is the magnitude of the force , in N, you must apply to keep the dweeb in equilibrium? (Use g = 10 m/s2) This scenario is represented schematically below.  Unfortunately for you, years later the dweeb is your boss and he makes your life miserable. (Please answer to the fourth decimal place - i.e 12.3445)

A block of mass m = 2.90 kg is pushed a distance d = 7.80 m along a frictionless horizontal table by a constant applied force of magnitude F = 16.0 N directed at an angle ? = 24.0° below the horizontal as shown in the figure below. A block labeled m is on a horizontal surface. An arrow labeled vector F points downward and to the right at an angle ? above the horizontal, and acts upon the upper left corner of the block. A faded image of the block is a distance d to the right of the block. (a) Determine the work done on the block by the applied force. J(b) Determine the work done on the block by the normal force exerted by the table. J(c) Determine the work done on the block by the force of gravity. J(d) Determine the work done by the net force on the block.

You have devised an experiment to measure the kinetic coefficient of friction between a ramp and a mass. You place the mass on the ramp at an angle high enough that the mass starts sliding. You measure the time it takes to fall down a known distance. The time it takes to fall down the 45 degree ramp starting from a standstill is At = 0.46 sec, m=1 kg, and the distance it falls, Ax , is 0.5 m. What is µk? m Дх in At Uk

Two crates of fruit  are released from the top of a ramp inclined at 30 degrees from the horizontal and 4.5 meter long. The two crates consist of  an apple crate of mass 20 kg that is placed in front of a watermelon crate of mass 80 kg.  The apple crate has a coefficient of friction of 0.20 while the watermelon crate has a coefficient of friction of 0.15. How long does it take the apple crate to reach the bottom of the incline if it needs to travel a distance of 4.5 meters?

A roller-coaster car is towed up an incline at a steady speed of 0.500 m/s by a chain parallel to the surface of the incline. The slope is 3.00%, which means that the elevation increases by 3.00 m for every 100.0 m of horizontal distance. The mass of the roller-coaster car is 594 kg. Ignoring friction, what is the magnitude of the force exerted on the car by the chain?

David throws a 50 kg cart down a ramp with an initial speed of vi = 6 m/s. The ramp is at an angle of 20◦, and the coefficient of kinetic friction between the cart and the ramp is µk = 0.25. Additionally, the coefficient of static friction is µs = 0.55. How much time does it take to reach Ryan who is 10 m away? Assume that the cart slides and doesn’t roll.

A block of mass m = 14kg rests on an inclined plane with a coefficient of static friction of mu_{s} = 0.11 between the block and the plane. The inclined plane is L = 6.8m long and it has a height of h = 3.95 m at its tallest point a. What angle in degrees does the plans make with respect to the horizontal B.what is the magnitude of the normal force, Fn in newtons that acts on the block C. What component of the force of gravity along with the plan fgx in newton? Will the block slide?

A warehouse worker exerts a constant horizontal force of magnitude 86.0 N on a 40.0 kg box that is initially at rest on the horizontal floor of the warehouse. When the box has moved a distance of 1.60 m, its speed is 1.00 m/s. What is the coefficient of kinetic friction between the box and the floor?

A block of mass m =1 kg, slides down a rough incline with constant velocity. The coefficient of kinetic friction between the block and the incline is µr, and the incline makes an angle 0 = 30° horizontal. Take g = 10 m/s2. The coefficient of kinetic friction µ is then equal to: v= constant with the O 0.577 O 0.466 O 0.422 O 0.364