Question

Calculate change in momentum of a car of mass 1000 kg when it's speed increase from 36 km h to 108 km h uniformly

Answer 1

Answer:

72000 kg-km

Explanation:

1000*(108-36)=72000

Answer 2

Answer:

The change in momentum of a car of mass 1000 kg when its speed increase from 36 km h to 108 km h uniformly will be $20000$ kgm/s

Explanation:

The momentum of an object can be defined as the product of mass and velocity.

$Momentum = mass\times velocity$

that is,

$P = mv$ ...(1)

Using equation (1),

Initial momentum,

$p_1 = mu$  

Final momentum,

$p_2 = mv$

Using the above equations,

The change in momentum ($\Delta P$) will be,

 $\Delta K.E = p_1 - p_2=\ mu - mv$

            $= m(v - u)$  ...(2)

Given,

Mass of the car (m) = $1000$ kg

Initial speed of the car  (u)      =  $36$ km/h

Final speed of the car  (v)       = $108$  km/h

Convert km/h into m/s by multiplying the velocity with $\frac{5}{18}$

$u = 36 \times \frac{5}{18}$ $= 10\ m/s$

$v = 108 \times \frac{5}{18}$$= 30 m/s$

Substitutes the values into equation(2).

$\Delta P = \ 1000\times( 30 - 10 )$

        $= 20000$ kgm/s

So, the change in momentum of the car $= 20000$  kgm/s