Question

A car is moving with a uniform velocity of 30 m s.
It is stopped in 2 s by applying a force of 1500 N
through its brakes. Calculate :
(a) the retardation produced in
car, and (b) the mass of the car.
Ans. (a) 15 m s-2 (b ) 100 kg​

Answer 1

Answer:

see this attachment

this problem can be solved by simple application of Newton's laws of motion .

Answer 2

» A car is moving with a uniform velocity of 30 s. It is stopped in 2 s by applying a force of 1500 N through its brakes.

Here..

• Initial velocity (u) = 30 m/s

• Final velocity (v) = 0 m/s

• Time (t) = 2 s

• Force (F) = 1500 N

_____________ [ GIVEN ]

We have to find (a) the retardation produced in car and (b) the mass of the car.

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a) At first we have to find the retardation produced in car. [means acceleration (a)]

Now..

» v - u = at

Put the known values in above formula

→ 0 - 30 = a(2)

→ 2a = - 30

→ a = - 15

For retardation ..

→ a = 15 m/s²

______________________________

b) In this we have to find the mass (m) of the car.

In question, we have given force too..

So, we can apply this formula to find the mass of the car.

» F = ma

Put the known values in above formula

→ 1500 = m(15)

→ 1500/15 = m

→ 100 = m

→ m = 100 kg

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