Question

A car moving with initial velocity of U is brought to rest by application of brakes whick provides uniform retardation of 2.5 ms -2 for 10 sec. The value of U is

Answer 1

ANSWER :--

→ U = 25 m/s

GiVeN :-

A car moving with initial velocity of U is brought to rest by application of brakes which provides uniform retardation of 2.5 m/s² for 10 sec.

• Deceleration, a = -2.5 m/s²
• Time, t = 10 s
• Final velocity, v = 10 m/s

To DeTeRmInE :-

→ The initial velocity (U) of the car.

AcKnOwLeDgEmEnT :-

According to the first law of kinematics :-

$\tt{\dag\ a=\dfrac{v-U}{t} }$

SoLuTiOn :-

Putting the values in the equation :-

$\tt{-2.5=\dfrac{0-U}{10} }\\\\\tt{\hookrightarrow -25=-U}\\\\\boxed{\boxed{\tt{\hookrightarrow U = 25\ m/s}}}$

Hence, the initial velocity of the car (U) is 25 m/s.

Answer 2

In the above ques , the following information is given -

A car moving with initial velocity of U is brought to rest by application of brakes whick provides uniform retardation of 2.5 ms -2 for 10 sec.

To find -

The value of U is -

Solution -

Here , the car is moving with an innitial Velocity u .

It is brought to rest .

So , the final velocity of the car is 0 m / s.

Acceleration of the car

=> -2.5 m / s²

Time taken for the car to stop = 10 seconds .

Now ,

According to the first law of motion -

V = u + at

Where ,

V is the final Velocity .

U is the innitial Velocity

a is the acceleration

t is the time .

Substituting the given Values -

0 = U + at

=> U = - at

=> U = - ( -2.5 ) × 10

=> U = 25 m/s

Hence , the innitial Velocity of the car is 25m/s .

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