You visited us 1 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard IX

Physics

Equations of Motion

A man is movi...

Question

A man is moving with 36 kmph. The time of reaction is 0.9 seconds. On seeing an obstacle in the path, he applies brakes and decelerates at 5 m/s², the total distance covered before he stops is:

18 m

No worries! We‘ve got your back. Try BYJU‘S free classes today!

17 m

No worries! We‘ve got your back. Try BYJU‘S free classes today!

16 m

No worries! We‘ve got your back. Try BYJU‘S free classes today!

19 m

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D
19 m

Given

u = 10 m/s

Distance covered within reaction time, d = u x t = 10 x 0.9 = 9 m

a = -5 m/s²

v = 0 m/s

we know that, a = (v - u) / t.

So, t = (v - u) / a = (-10)/(-5) = 2s

We also know that, the distance is given as

s = ut + (1/2) at²

s = (10) (2) + (1/2) (-5)(2)(2)

s = 20 + (-10) = 10

Total displacement = 9 + 10 = 19

Suggest Corrections

Similar questions

A man is moving with 36 kmph. On seeing an obstacle in the path, he applies brakes and decelerates at 5 m/s2, if the time of reaction is 0.9 seconds. Then the total distance covered before he stops is:

Q. A man is driving at the speed

40 m p h

when he see an obstacle at distance

300 f t

ahead of his position. The driver applies the brakes and decelerates at

10 f t / s^{2}

.How far from the obstacle will the driver be when he finally stops? (in metres)

Q. A car is moving with speed

20 m / s

. Suddenly the driver sees the sign of danger at a distance of

50 m

; after a certain reaction time

t_{0}

he applies brakes to cause deceleration

5 m / s^{2}

. What is the maximum allowable reaction time

t_{0}

to avoid accident and distance travelled by the during reaction time?

Q. A car is moving at a speed of

72 k m / h r

on a road having

2 %

upward gradient. The driver applies brakes when he sees an obstruction. If his reaction time is

1.5 seconds

, assuming that the coefficient of friction between the pavement and tyre as

0.15

, calculate the distance traversed before the car finally stops

Q. The driver of a car moving at a speed of

10 m/s

applies the brakes after noticing an obstacle. The retardation due to the brakes is

4 {m/s}^{2}

. What is the distance travelled by the car till it stops?

Join BYJU'S Learning Program

A man is moving with 36 kmph. The time of reaction is 0.9 seconds. On seeing an obstacle in the path, he applies brakes and decelerates at 5 m/s2, the total distance covered before he stops is:

A man is moving with 36 kmph. The time of reaction is 0.9 seconds. On seeing an obstacle in the path, he applies brakes and decelerates at 5 m/s², the total distance covered before he stops is: