Car b is initially stationary and is struck by car a moving with initial speed v1 = 20 mi / hr. the cars become entangled and move together with speed v′ after the collision. if the time duration of the collision is 0.1 sec, determine (a) the common fi nal speed v′, (b) the average acceleration of each car during the collision, and (c) the magnitude r of the average force exerted by each car on the other car during the impact. all brakes are released during the collision

An engine, weighing 3000 n, is supported on a pedestal mount. it has been observed that the engine induces vibration into the surrounding area through its pedestal at the maximum operating speed. determine the stiffness of the dynamic vibration absorber spring in (n/m) that will reduce the vibration when mounted on the pedestal. the magnitude of the exciting force is 250 n, and the amplitude of motion of the auxiliary mass is to be limited to 2 mm note: in this question type-in right numbers, no decimals, no fractions, no unit. approximate to right number if needed