A car collided with a telephone pole and left 20 ft skid marks on the dry pavement. Based on the damages sustained, an engineer estimated that the speed at collision was 15 mi/h. If the roadway had a 3% grade, calculate the speed of the car at the onset of skidding.

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