Question

driving home from school one day you saw a ball rolling down into the street you brake for 1.10s slowing your 950 kg 16.0m/s to 9.50 m/s

Answer 1

a ) v = v o + a t ( the acceleration will be negative )

9.50 = 16.0 + a * 1.2

a * 1.2 = -16.0 + 9.50

a * 1.2 = - 6.5

a = - 6.5 : 1.2

a = - 5.4167 m/s²

F = m * a = 950 kg * 5.4167 m/s²

F = 5,145.8 N ( the average force exerted on a car during braking )

b ) d = v o - a t² / 2

d = 16.0 * 1.2 - ( 5.4167 * 1.2² / 2 ) =

= 19.20 - 3.90 = 15.30 m