Question

. A car is moving with uniform speed of 36 km/h in a straight road. Suddenly a rickshaw crosses the road

just 100 m ahead of the car. If the reaction time for the driver is 2 seconds, what must be the retardation

just to avoid the accident?​

Answer 1

Given:
Initial speed of the three-wheeler, u=36km/h=10m/s
Final speed of the three-wheeler, v=0 m/s
Time, t=4s
Mass of the three-wheeler, m=400 kg
Mass of the driver, m
′
=65kg
Total mass of the system, M=400+65=465 kg
Using the first law of motion, the acceleration (a) of the three-wheeler can be calculated as:
v=u+at

a=
t
(v−u)
​
=
4
(0−10)
​
=−2.5m/s
2

The negative sign indicates that the velocity of the three-wheeler is decreasing with time.

Using Newton's second law of motion, the net force acting on the three-wheeler can be calculated as:
F=Ma=465×(−2.5)=−1162.5N
The negative sign indicates that the force is acting against the direction of motion of the three-wheeler.

Answer 2

Explanation:

sry this question answer i odnt know