The Johnsons just received a heavy package (perhaps a treadmill) in the mail that they ordered from a popular online shopping website. It's so heavy that they had to push it across their carpeted floor since it was too heavy to lift. The item weighs 102.1 kg and it's packaged in cardboard. The coefficient of friction between the cardboard and their carpet is 0.52.  They're a team, and they all push the huge package across their living room at a constant speed. How much collective force do they have to use to push the package across the living room at a constant speed of 0.11 m/s? Use the approximation g ≈ 10 m/s2 Answer: _____________ N (round to nearest whole number)

It's a snowy day and you're pulling a friend along a level road on a sled. You've both been taking physics, so she asks what you think the coefficient of friction between the sled and the snow is. You've been walking at a steady 1.5 m/s, and the rope pulls up on the sled at a 41° angle. You estimate that the mass of the sled, with your friend on it, is 56 kg and that you're pulling with a force of 88 N. Part A What answer will you give? 5 ΑΣΦ Submit Request Answer < Return to Assignment Provide Feedback ?

A teenager is pushing a cart.  There is no friction between the cart and the ground. Mass of the cart is 120 kg. Cart is initially at rest (at time = 0 s). Direction to the right is positive. He pushed the cart for 5 s (from t = 0 s to t = 5 s) with a force of 75 N to the right hand side. Then he stopped pushing for 5 s (from t = 5 s to t = 10 s). Then he pushed the cart for 10 s (from t = 10 s to t = 20 s) with a force of 75 N to the left hand side.  Question: Calculate the kinetic energy of the cart at  t = 5 s.

I am not sure what formula to use in this question!

Two horizontal forces, P and Q, are acting on a block that is placed on a table. We know that P is directed to the left but the direction of Q is unknown; it could either be directed to the right or to the left. The object moves along the x-axis. Assume there is no friction between the object and the table. Here P = -6.1 N and the mass of the block is 3.8 kg. P (a) What is the magnitudeand direction of Q (in N) when the block moves with constant velocity? (Indicate the direction with the sign of your answer.) 6.1 N (b) What is the magnitude and direction of Q (in N) when the acceleration of the block is +7.5 m/s2. (Indicate the direction with the sign of your answer.) X 22.4 The acceleration given here is due to the net force acting on the object. N (c) Find the magnitude and direction of Q (in N) when the acceleration of the block is -7.5 m/s2. (Indicate the direction with the sign of your answer.) X -34.6 What is the direction of motion of the object when the acceleration is…

The quadriceps tendon passes over the kneecap and presses on the temur. The tension in the tendon is F = 1000 N. What is the magnitude of the resultant force of the kneecap acting on the femur for the angles as shown in the diagram (to the nearest 100 N)? Kneecap 1500 N 2000 N 120 N 1300 N 600 N 300 N

The figure below shows a bird feeder that weighs 167.9 N. The feeder is supported by a vertical string, which is in turn tied to two strings, each of which is attached to a horizontal branch. The left string makes a 60° angle with the branch, while the right string makes a 30° angle. What is the tension in each string (in N)?   left string __N right string __N bottom string __N

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.

A boy has filled his toy box with all his favorite toys and it trying to drag it across the floor. The toy box has a mass of 35 kg (including the toys) and the child pulls with a force of 24 N at an angle of 30 degrees above horizontal (he is pulling mostly horizontally, but some of the force is pulling up). How will the normal force between the box and the ground change when the boy starts pulling?

A rope is attached to an object with mass 4.1-kg that rests on a frictionless, horizontal surface. The horizontal rope passes over a pulley, and a block with mass 5 kg is suspended from the other end. When the blocks are released, the tension in the rope is 17.6 newtons. What is the acceleration of either block?  The pulley is frictionless and massless.