Question

A car travelling at 80 m/s is braked so as to produce a retardation of 4 m/s2. After what time wil
its speed be 40 m/s and what will be the distance travelled during this time? (10 s; 600 m)

Answer 1

Explanation:

u = 80m/s

v = 40m/s

a = -4 m/s²

From v = u + at,

40m/s = 80m/s - 4t

- 40 = - 4t

t = 10s

From S = ut + 1/2at²,

S = 80*10 - 2*100

S = 800 - 200

S = 600m