NEWTONS LAWS, WORK AND ENERGY Instruction: Answer each number neatly. Solutions must also be shown and enclose your fatal answer with a box. No solution, no points. 1. A box sits at rest on a rough 30 incline plane. a. Draw the freebody diagram showing all the forces acting on the box. b. How would the diagram change if the box were sliding down the plane? c. How would it change if the box were sliding up the plane after an initial shove? 2. Two boxes are oonnected by a lightweight cord and are resting on a table. The boxes have masses 12 kg and 10 kg. A horizontal force of 40 N is applied by a person to the 10 kg box as shown in the gure below. Find a. the aoceleration of each box b. the tension in the cord n2312|q unk. 3. A 3.00kg block starts from rest at the top of a 30.0\" incline and slides a distance of 2.00 in down the incline in 1.50 s. Find [a] the magnitude of the acceleration of the block, [bl the coefcient of kinetic friction between block and plane, to] the friction force acting on the block, and (d) the speed of the block after it has slid 2.00m. 3. A 3.00kg block starts from rest at the top of a 30.0\" incline and slides a distance of 2.00 m down the incline in 1.50I s. Find [a] the magnitude of the acceleration of the block, (b) the coefcient of kinetic friction between block and plane, [c] the friction force acting on the block, and (d) the speed of the block after it has slid 2.00m. 4. a. Determine the work a person must do to carryr a 15.0 kg backpack up a hill of height h = 10.0 m. b. Determine also the work done by gravity on the backpack. c. Determine also the net work done on the backpack. For simplicity, assume the motion is smooth and at constant velocity [i-e., there is negligible acceleration). 5. A 1000 kg roller coaster car moves from point A, referring to figure below, to point B and then to point C. 10 m a. What is the gravitational potential energy at B and C relative to point A? That is, A take y = 0 at point A. 15 m b. What is the change in potential energy C when it goes from B to C? 6. A ball of mass m = 2.60 kg, starting from rest, falls a vertical distance h = 55.0 cm before striking a vertical coiled spring, which it compresses an amount Y = 15.0 cm. Determine the spring constant of the spring. Assume the spring has negligible mass. initial final 7. A 2 kg block is released from rest at point A on a track, which is one quadrant of a circle of radius am as in the figure below. It slides down the track A and reaches point B with a speed of 4 m/s. From point B, it slides on a level surface a distance of 3 r = 1m m to point C, where it comes to rest. a. What was the coefficient of sliding friction on the horizontal surface? b. How much work was done against friction as B the body slid down the circular arc from A to B