Question

< Problem Assignment No. 8 Principle of Impulse and Momentum 6 of 20 Learning Goal Part A Time for the Car to Reach 100 km/h To apply the concepts of impulse and momentum to problems involving unknown forces, velocities, and times Find the time it will take for the car to reach v 100 km/h from rest. Express your answer to three significant figures in seconds A new rear-wheel drive automobile design is being tested and you have been asked to estimate its performance. The car without wheels (i.e., the body) has a mass of m 1550 kg The wheels (including tires) have diameter of 59.0 cm and each wheel weighsm 15.0 kg. The radius of gyration of the wheels about their centers is k 17.2 cm. Model the torque output (which acts in the counterclockwise direction) to each rear wheel as T(t) 90.0 t3/2 N- m. Assume that the wheels roll without slipping and neglect the air resistance and any other frictional effects View Available Hint(s) vec (Figure 1) Submit Request Ans Part B - Force Exerted by the Brakes After the car reaches 100 km/h the driver immediately steps on the brakes and comes to a stop in 2.75 s. The brakes are at a distance 15.9 cm from the center of the wheel and the force they apply acts in the y direction. Assume for this problem that the brakes apply an equal force to each wheel that the torque to the rear wheels is zero and that the wheels continue to rotate until the car stops. Calculate the magnitude of the force, Fb, exerted by the brakes on each wheel during this time Express your answer to three significant figures and include the appropriate units View Available Hint(s) Figure 1 of 1 FValue Units Submit Provide Feedback Next >

Answer 1

dl 08 3 180 xt sec

9.S こ30 , 39 Nm. F x o 15930 39 191-138 N