Question

A car initially moving at 35 km/h along a straight highway. To pass another car, it speeds up to 135 km/h in 10.5 seconds at a constant acceleration. How large was the acceleration in m/s^2? How large was the acceleration in units of g= 9.80 m/s^2

Answer 1

We calculate the difference between the two velocities,
                                 135 km/h - 35 km/h  = 100 km/h
Then, convert the difference into units of m/s
                         100 km/h x (1000 m/ 1 km) x (1 hour / 3600 s)  = 27.78 m/s
Then divide the difference by time.
                       acceleration = 27.78 m/s / 10.5 s = 2.65 m/s²

(2) In terms of g,
                               x = 2.65 / 9.80 = 0.27
  Therefore, the answer would be,
                                     a = 0.27g