Assume that before the accident happened, the car was going at a constant velocity of 60Km/h on a level highway for a distance of 10.0km. The car accelerated briefly to 70.0Km/h to pass another car and then returns to 60.0Km/h as it descends the other side of the hill, even though the driver has taken her foot off the accelerator. Identify the times when the car’s engine was doing work on the car. Explain your answers.

Calculate the work done by friction as a 3.7 kg box is slid along a floor from point A to point B in the figure along paths 1, 2, and 3. Assume that the coefficient of kinetic friction between the box and the floor is 0.19. (Figure 1) Enter your answers numerically separated by commas. Express your answers using two significant figures.   W1,W2,W3= ______ J

A mechanic pushes a 2.90 ✕ 103-kg car from rest to a speed of v, doing 4,530 J of work in the process. During this time, the car moves 20.0 m. Neglecting friction between car and road, find v and the horizontal force exerted on the car. (a) the speed v m/s (b) the horizontal force exerted on the car (Enter the magnitude.) N

6. A 2 kg cart travelling 4 m/s to the right collides with and sticks to a 6 kg cart that was initially travelling 1 m/s to the left. Find the value of the velocity of the carts after the collision. 2 kg 6 kg A block of mass m is pushed with a constant force Fpush across a horizontal floor with a cooeficient of kinetic friction μK for a distance d. (probs. 7&8) 7. Draw a free body diagram labelling ALL of the forces acting on the block and find an expression for the work done by each. 8. After the block is pushed d there is no more pushing and it slides another d until it comes to a stop. Assuming d = 5 m, Fpush = 20 N, m = 5 kg and correctly using AK + AU =W₂ find the value of μк. NC'

Determine the work done on the block? Determine the final speed of the block?

A block slides across the ground and comes to rest in 12.0 m. muk = 0.200. Find the initial speed using conservation of E. Correct answer: 6.86 m/s

Problem 9: A roller coaster, shown in the figure, is pulled up to point A where it and its screaming occupants are released from rest. Assuming no friction, calculate the speed at points B, C, D. A m 22 m B C 32 m 16 m

A mechanic pushes a 3.20 X 103-kg car from rest to a speed of v, doing 5,340 J of work in the process. During this time, the car moves 20.0 m. Neglecting friction between car and road, find v and the horizontal force exerted on the car. (a) the speed v m/s (b) the horizontal force exerted on the car (Enter the magnitude.) N

on an essentially frictionless, horizontal ice rink, a skater moving at 6.0 m/s encounters a rough patch that reduces her speed by 48 % due to a friction force that is 25 % of her weight. Part A. Use the work-energy theorem to find the length of this rough patch. Express your answer using two significant figures.

A mechanic pushes a 3.20 × 103 - kg car from rest to a speed of v, doing 5, 340 J of work in the process. During this time, the car moves 20.0 m. Neglecting friction between car and road, find v and the horizontal force exerted on the car. (a) the speed v m/s (b) the horizontal force exerted on the car (Enter the magnitude.) N