sled of 50 kg mass moves along a smooth horizontal surface at 7 m/s. The sled encounters a rough spot that exerts a force of -90 Nt on the sled.  Calculate: a) What is the acceleration of the sled? b) Calculate how much work is done by the frictional force on the sled if the patch is 15 m in length. c) What is the sled's final velocity as it leaves the rough spot?

9.) A 65.0-kg file cabinet of is sliding down a rough ramp for a distance of 5.00 m as shown. The friction force on the box is 75.0 N. During this process, what is the work done on the cabinet by the friction force, in Joule? Use g = 10.0 m/s2. Your answer needs to have 3 significant figures, including the negative sign in your answer if needed. Do not include the positive sign if the answer is positive. No unit is needed in your answer, it is already given in the question statement.

1) A 1622 kg car has a speed of 11.3 m/s whenit hits a tree. The tree doesn’t move and thecar comes to rest.Find the change in kinetic energy of the car.Answer in units of J. 2)Find the amount of work done by the car asits front is pushed in.Answer in units of J. 3)Find the magnitude of the force that pushedthe front of the car in by 37 cm .Answer in units of N.

Stopping distance. A car is traveling on a horizontal road with speed v_0=13.9 m/s at the instant the brakes are locked, so the tires are sliding instead of rolling. Use the work-energy theorem to calculate the minimum distance the car can stop if the coefficient of kinetic friction \mu_k=0.7 between the tires and the road. B: A: 12 m 16 m C: 17.5 m D: 14 m. E: 23.7 m

A 10 kg block experiences a frictional force of 8.66 N as it slides 2m down an incline as shown. As please 30 a) Draw a Free Body Diagram for the block and include As. b) Find the coefficient of kinetic friction between the block and the incline 19) As the block moves 2m down the incline, find W, the work done on it by gravity, d) As the block moves 2m down the incline, find Wr, the work done on it by friction. le) Using Wnat = AK, find the block's kinetic energy, Ke when the block has moved 2m down the incline, If its velocity at the top of the incline was 1 m/s. 1F) Now assume there was an additional force P on the block pointing up the incline. Find W, the work done by P, so that the block moved down the incline with a constant speed.

Three objects with masses m, = 6.6 kg, m, = 14 kg, and m3 = 16 kg, respectively, are attached by strings over frictionless pulleys as indicated in the fiqure below. The horizontal surface exerts a force of friction of 30 N on m,. If the system is released from rest, use energy concepts to find the speed of m, after it moves down 4.0 m. m/s m2 m1

3. A student drags a 3 kg box 5 m across a rough floor with a force of 40 N. A frictional force of 10 N resists the motion of the box. A) Calculate the work done by the student. B) Calculate the work done by friction. C) Determine the net work done on the box. D) If the box started from rest, how fast is it going at it approaches 5 m? has a yelocity of 8

= 13 kg, and m3 20 kg, respectively, are attached by strings over frictionless pulleys as indicated in the figure below. The horizontal surface 3.4 kg, m2 %3D Three objects with masses m, exerts a force of friction of 30 N on m,. If the system is released from rest, use energy concepts to find the speed of m, after it moves down 4.0 m. m/s m2 m1 m3

Energy (1).pdf 2 / 3 T Problem 9: A 3 kg block is pushed 3 m up a 30° incline by a 50 N force aligned parallel to the ramp. The coefficient of kinetic friction between the ramp and the block is 0.2. a) Calculate the work done by gravity. b) Calculate the work done by the applied force. c) Calculate the work done by the normal force. d) Calculate the work done by the friction force. e) Calculate the net work done on the block. f) Find the speed of the block after traveling this distance. Assume it started at rest. 110% Pr TI re W sp ha A: ar ax Pr A pe of re

1480 kg car accelerates uniformly from a position of rest to a speed of 95 km/h in 6.0 s. a) Calculate the car's acceleration. b) How far did the car travel during this acceleration?  b) How much work was done by the car during this 6.0 s?