8. A child pulls a friend in a little red wagon with constant speed. If the child pulls with a force of 16 N for 10.0m, and the handle of the wagon is inclined at an angle of 25° above the horizontal, how much work does the child do on the wagon? Assume the mass of the wagon system is 45 kg. What is the coefficient of friction between the wagon and the ground? If the friction force remains the same when the force applied by the child is doubled, what will the final speed of the wagon be after travelling from rest for a distance of 10m? 3

How much work is done in lifting a 300-kg marble slab to a height of 50m on a building under construction? 2. Eating a banana enables a person to perform about 4.0 x 104 J of work. To what height does eating a banana enable a 70-kg heart patient to climb. 3. Calculate the work done by a mother who exerts a force of 8 N at an angle of 40° below the horizontal x-axis in pushing her baby in a carriage to a distance of 20m.

2. A constant force of 1200 N is required to push a car along a straight line. A person displaces the car 45 m. How much work is done by the person?

S 10. A box of mass 7.60 kg is pulled from rest up a 46.5 m long incline that makes an angle of 22.0° with horizontal. The coefficient of kinetic friction between the box and the incline is 0.200. At the top of the incline, the speed of the box is 4.50 m/s. What is the work done by the pulling force? J E L C 2 R F 5 T G 6 MacBook Air B 00 S Y 7 Submit Assignment H S N J 9 M K MOSISO ge command

Two men, Joel and Jerry, push against a wall. Jerry stops after 10 min, while Joel is able to push for 5.0 min longer. Compare the work they do. Select one: а. Both men do positive work, but Jerry does 50% more work than Joel. b. Both men do positive work, but Joel does 50% more work than Jerry. С. Neither of them does any work. d. Both men do positive work, but Joel does 75% more work than Jerry. е. Both men do positive work, but Joel does 25% more work than Jerry.

A person is accelerating a box across the floor using a force Fpull for a distance d. There is a force of friction on the box Ff. How would you expect the amount of net work done in the x-direction (Wnet) to compare to Wpull, the amount of work done by the pulling force? Wnet = Wpull because Wpull is calculated using the net force Wnet Wpull because the friction force also does work Wnet = 0 because the pulling force and the friction force cancel out

A 5.40-kg box rests on a horizontal surface. The coefficient of kinetic friction between the box and surface is µk 0.410. A horizontal force pulls the box at constant velocity for 23.0 cm. Find the work done by the applied horizontal force. Submit Answer Tries 0/10 Find the work done the frictional force. Submit Answer Tries 0/10 Find the work done by the net force. Submit Answer Tries 0/10

Problem 7: Rescue workers lower a sled and injured ice climber, with a combined mass of 95 kg, down a 60° slope at a constant speed as shown in the diagram. The coefficient of kinetic friction between the sled and the snow is 0.1. Suppose the sled is lowered 30 m along the hillside. a) How much work is done by friction as the sled/climber moves along the hill? b) How much work is done by the gravitational force as the sled/climber moves along the hill? c) How much work is done by the tension force in the rope as the sled/climber moves along the hill? d) What is the net work done on the sled/climber? 60° W T

A metalsmith at a foundry drags a hunk of steel across the horizontal foundry floor by pulling on it with a 320 N force angled 28° above the floor. If the kinetic friction force due to the floor is essentially constant at 280 N, what is the net work done on the hunk of steel by both the metalsmith and kinetic friction over a distance of 11 m? A. 3100 J B. 3500 J C. 440 J D. 28 J

A grocery cart with a mass of 10 kg is being pushed at constant speed up a 25° ramp by a force Fp which acts parallel to the incline. (Ignore the friction) a. Draw a free-body diagram of the cart showing all the forces acting on it.  b. Find the work done by each of the forces (W, Fn, Fp) on the cart if the ramp is 7.5 m long.  Hints: The question is very similar to the question of a piano sliding down an incline discussed in class. However, here the object is pushed up the incline. The forces Fn = mgcos(0), and Fp = mgsin(0), so don't spend time getting these using Newton's 2nd law. Also, the weight is W = mg. c. Find the net work done on the cart.