Sammy is doing a strength testing session on the turf in preparation for the upcoming basketball season.  Sammy's mass is 55 kg and she is trying to push a 105 kg sled across the artificial turf outside on Raymond Field.  The coefficient of static friction between the sled and the turf is 0.3.  If Sammy pushes only horizontally against the sled, how much force must she push with to just initiate movement of the sled? (hint: be sure to follow the steps outlined for free body diagrams, including drawing the free body diagram with all forces, force equations in the X and Y direction, and a coordinate system)

Two blocks A and B with mA = 1.1 kg and mB = 0.88 kg are connected by a string of negligible mass. They rest on a frictionless horizontal surface. You pull on block A with a horizontal force of 6.7 N. How will the tension in the string be affected if mA is decreased?

You are helping your friend unload their moving truck. You are starting to get lazy, so you just set the boxes on the ramp down to the ground to let them slide down. You try to do the same with a small chair, but notice that it slides down the ramp much more slowly. Being a budding physicist, you reason that this is because the chair/ramp combination has a larger coefficient of kinetic friction than the boxes/ramp combination. The chair accelerates down the ramp at 0.72 ? ? 2 . The ramp is at an angle of 31° below the horizontal and the chair has a mass of 13 ??. Find the coefficient of friction between the chair and the ramp. Draw a free body diagram 2. Set up a coordinate system. You must correctly follow our rule to align the net acceleration for the system to be along a single axis (it cannot have an x- and a y-component). Correctly set up Newton’s Second Law (sum of the forces) in both the x- and y- direction. Correctly use either sinθ or cosθ as appropriate.

Two adults and a child want to push a wheeled cart in the direction marked x in the figure. The two adults push with horizontal forces Fs1 and Fs2 as shown. (a) Find the magnitude and direction of the smallest force that the child should exert. Ignore the effects of friction. (b) If the child exerts the minimum force found in part (a), the cart accelerates at 2.0 m/s^2 in the +x-direction. What is the weight of the cart?

The longer, top cord loops over a frictionless pulley and pulls with a force of magnitude 74 N on the wall to which it is attached. The tensions in the shorter cords are T1 = 40.0 N, T2 = 32.0 N, and T3 = 8.0 N.   What are the masses of each disk? (a) disk A kg(b) disk B kg(c) disk C kg(d) disk D kg

In the figure below, a box of Cheerios (mass mc = 1.5 kg) and a box of Wheaties (mass mw = 2.7 kg) are accelerated across a horizontal surface by a horizontal force F applied to the Cheerios box. The magnitude of the frictional force on the Cheerios box is 2.0 N, and the magnitude of the frictional force on the Wheaties box is 4.1 N. If the magnitude of F is 12 N, what is the magnitude of the force on the Wheaties box from the Cheerios box? |---Select--- mc Mw

The coefficient of static friction between an 8 kg box at rest and a 35° inclined plane is 0.70. Determines whether the object starts moving or stays in a static state. Justify your answer. If the object starts moving, what happens to the coefficient of friction? Also, describes the movement of the box.

A 1280 kg car pulls a 350 kg trailer. the car exerts a horizontal force of 3.6 x 103 N against the ground in order to accelerate. What force does the car exert on the trailer? Assume an effective friction coefficient of 0.15 for the trailer.

If the coefficient of kinetic friction, lk, between the block and the surface is 0.40 and the magnitude of the frictional force is 80.0 N, what is the weight of the block? 1.6 N 160 N 166 N 200 N 410 N

F(t) Force_Crate Known values: Mass of Block 68 kg TT Hs μk 0 0.63 0.53 26° Problem Statement: A crate is initially at rest on a sloped surface, when a force is applied: F(t) where t is in seconds. Answers: When t=44.47 seconds, the crate has not yet started moving. Find the magnitude of the friction force at that time: 317.771 N The direction of the friction force at that time is: down the slope Find the time required for the crate to start moving: Find the crate's speed when t=174.9 s: 9.485 m/s Be sure to include units with your answers. 169.756 S 240+0.2 N,