Question

Time it took to break a car at 30 mph, 1 second. Calculate the average braking acceleration ¯a (m/s2 ) and record the result (to the nearest 0.1 m/s2 ) as the answer to part (b) of this problem. Also calculate the average braking acceleration in terms of g (g = 9.80 m/s2 ) and record the result (to the nearest 0.01g) as the answer to part (c) of this problem. Note: Enter all of your answers as positive values.

Answer 1

here,

the initial speed of car , u = 30 mph = 13.41 m/s

time taken , t = 1 s

let the average accelration be a

as final speed is zero

0 = 13.41 + a * 1

a = - 13.4 m/s^2

the average accelration is - 13.4 m/s^2

a = - 13.4 /9.81 * g

a = - 1.37 g