Question

A car is moving with a velocity of 10 m/s. The driver sees a wall ahead of him and applied brakes. The car stops after covering 10 m distance. If the car was moving with a speed pf 20 ms −1 , it would have stopped in 30 m distance. The reaction of the driver is

Answer 1

Explanation:

V = 0m/s

u = 20m/s

s = 10m

2as = v² - u²

2×a×30 = -400

a = -400/60 = -100/15 m/s

.........

now,

v = 0m/s

u = 15m/s

a = - 20m/s

2as = v² - u²

2×-100/15×s = -225

s = 225/200/15 = 16.875m

Answer 2

Answer:

V = 0m/s

u = 20m/s

s = 10m

2as = v² - u²

2×a×30 = -400

a = -400/60 = -100/15 m/s

.........

now,

v = 0m/s

u = 15m/s

a = - 20m/s

2as = v² - u²

2×-100/15×s = -225

s = 225/200/15 = 16.875m

Explanation: