38. A 1100 kg car travels on a straight highway with a speed of 30 m/s. the driver sees a red light ahead and applies the brakes until the car stops, which exerts a constant braking force of 4000 N. Compute the deceleration of the car.
) 39. Figure 3 shows an object M which has a mass of 10 kg. If the inclined surface is rough with the coefficient of friction between the object and the incline plane is 0.2. As the object M slides down the incline: i. Sketch all the forces acting on object M, ii. Calculate the magnitude of acceleration of object M.
40. Block A of mass 30 kg is at rest on a 40° inclined rough plane with coefficient of friction 0.15. The block is attached by a light string to block B with a mass of 40 kg, as shown in Figure 3. i. Compute the tension in the string.
ii. Draw the free body diagram for block A and block B. iii. Determine the frictional force exerted on block A.