Question

Starting from a stationary position,a car attains a velocity of 6 metre per second in 30 second driver of the car applies brakes such that velocity of the car comes down to 4 metre per second in the next 5 second calculate the acceleration of the car in both the cases.

Answer 1

Given : -

•A car travels a velocity of 6m/sec in 30sec.

•Velocity of the car comes to 4m/sec in the next 5 sec.

To Find : -

•Find the acceleration of the car in both cases.

Solution : -

Since,car starts from the stationary position.So in first case,u = 0,v = 6m/s ,t = 30s

Now,

$\: \sf \large \: a = \frac{v - u}{t}$

Now substitute the values

$\: \sf \: a = ( \frac{6 - 0}{30} ) \\ \\ \: \sf \: a = 0.2 \frac{m}{ {s}^{2} }$

In the second case,the driver applies the brakes.So,

• u = 6m/s
• v = 4m/s
• t = 5s

$\: \sf \implies \: a = ( \frac{4 - 6}{5} ) \frac{m}{ {s}^{2} } \\ \\ \: \sf \implies \: a = - 0.4 \frac{m}{ {s}^{2} }$

Hence,acceleration of the car is -0.4m/s^2.

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