Question

by how much does the momentum of a body of mass 5 kg change when it's speed decreases from 20 m/s to 0.20m/s

Answer 1

Answer:-

p = 99 kg m/s

Given:-

m = 5 kg

v = 20 m/s

To find the change in momentum.

Solution:-

Momentum :- The product of mass and velocity is known as momentum.

Let the momentum of the body be $p_1$ after changing its velocity it becomes $p_2$.

From definition,

$\huge \boxed{P = mv }$

→$p_1 = 5 \times 20$

→$p_1 = 100 kg m/s$

Now,

when, v = 0.20 m/s

→$p = 5 \times \dfrac{20}{100}$

→$p = 5 \times \dfrac{1}{5}$

→$p = 1 kg m/s$

Now, change in momentum :-

$p = p_1 - p_2$

→$p = 100 - 1$

→$p = 99 kg m/s$

hence,

The change in momentum will be 99 kg m/s.

Answer 2

Answer:-

p = 75 kg m/s

Given:-

m = 5 kg

v = 20 m/s

To find the change in momentum.

Solution:-

Momentum :- The product of mass and velocity is known as momentum.

Let the momentum of the body be $p_1$ after changing its velocity it becomes $p_2$.

From definition,

$\huge \boxed{P = mv }$

→$p_1 = 5 \times 20$

→$p_1 = 100 kg m/s$

Now,

when, v = 0.20 m/s

→$p = 5 \times \dfrac{20}{100}$

→$p = 5 \times \dfrac{1}{5}$

→$p = 1kg m/s$

Now, change in momentum :-

$p = p_1 - p_2$

→$p = 100 - 1$

→$p = 99 kg m/s$

hence,

The change in momentum will be 75 kg m/s.