Question

A car of mass 1200 gram is moving with a velocity of 108 km per hour on applying brakes is its velocity is reduced to 36 km per hour find the change in momentum

Answer 1

Answer:

Explanation:

Solution,

Here, we have

Mass, m = 1200 kg

Initial velocity, u = 108 km/h = 108 × 5/18 = 30 m/s

Final velocity, v = 36 km/h = 36 × 5/10 = 10 m/s

To Find,

Change in momentum = ?

According to the formula,

We know that,

Change in momentum = Final momentum - Initial momentum

i.e, Change in momentum = m(v - u)

So, putting all the values, we get

⇒ Change in momentum = m(v - u)

⇒ Change in momentum = 1200(10 - 30)

⇒ Change in momentum = 1200 × (- 20)

⇒ Change in momentum = - 2400 kg.m/s

Hence, the change in velocity is - 2400 kg.m/s

Answer 2

Here question is having some error mass of car can't be 1200 gram its 1200 kilo grams.

Momentum is defined as the product mass and velocity.

$\implies \bold{\bf{\red{P=m\Delta v}}}$

Given ,

mass , m = 1200 kg

Initial velocity , u = 108 km /h = 108 * (5/18) = 30 m/s

Final velocity , v = 36 km/h = 36 * (5/18) = 10 m/s

⇒ Δv = v-u = 10 - 30 = -20 m/s

$\bold{Now\;,\;Momentum,P=m\Delta v}\\\\\implies \bold{P=1200(-20)}\\\\\implies \bold{\bf{\blue{P=-2400\;kg.m/s}}}$