Question

27 )27.A body is moving with a velocity of
18 km/h increases 36 km/h in 10
seconds. If mass of the body is 1000 kg
calculate the force exerted on the body.
3​

Answer 1

Explanation:

Given that,

Mass m=1000kg

Speed v

1

=36km/h=10m/s

Speed v

2

=108km/h=30m/s

We know that,

The change in momentum

ΔP=m(Δv)

ΔP=m×(v

2

−v

1

)

ΔP=1000×(30−10)

ΔP=2×10

4

kgm/s

Hence, the change in momentum is 2×10

4

kgm/s

Answer 2

Given,

A body is moving with a velocity of  18 km/h increases 36 km/h in 10  seconds and the mass of the body = 1000 kg.

To Find,

The force exerted on the body.

Solution,

Initial velocity (u) = 18 km/hr

Final velocity (v) = 36 km/hr

Time taken (t) = 10 seconds

Mass of the body (in kg) = 1000 kg

Acceleration (a) = $\frac{v-u}{t}$ = $\frac{36 - 18}{10}$ = $\frac{18}{10}$ = $\frac{9}{5}$

✔ Newton's second law states that the Force exerted on the body is equal to the product of the mass and the acceleration of the body.

✔ F = ma

Taking the formula, F = ma and substituting the values.

F = 1000 x $\frac{9}{5}$

  = 1800 N

Therefore the force exerted on the body is 1800 N.