Question

A mass of $200gm$ has initial velocity $V_i=2\hat{i}+3\hat{j}$ and final velocity $-2\hat{i}-3\hat{j}$. Find magnitude of change in momentum.

• A. $|\Delta \overrightarrow{p}|=3.84$
• B. $|\Delta \overrightarrow{p}|=3.04$
• C. $|\Delta \overrightarrow{p}|=1.44$
• D. $|\Delta \overrightarrow{p}|=2.04$

Answer 1

The correct option is C $|\Delta \overrightarrow{p}|=1.44$

Given,

$|\Delta \overrightarrow{P}|=1.44$

Given,

$m=200gm=0.2kg$

Initial velocity, $

${\overrightarrow{v}}_i=2\hat{i}+3\hat{j}$

Final velocity, ${\overrightarrow{v}}_f=-2\hat{i}-3\hat{j}$

Change in magnitude, $\Delta P=m(v_f-v_i)$

$\Delta P=0.2(-4\hat{i}-6\hat{j})$

$\Delta P=-0.8\hat{i}-1.2\hat{j}$ in vector form.

The magnitude of change in momentum is

$|\Delta P|=\sqrt{(-0.8{)}^2+(-1.2{)}^2}$

$|\Delta P|=1.44$