Question

Two masses of $1g$ and $4g$ are moving with equal kinetic energies. The ratio of the magnitudes of their linear momenta is:

• A. $4:1$
  
• B. $2:1$
  
• C. $1:2$
  
• D. $1:16$
  

Answer 1

The correct option is B $2:1$

We know,

$KE=\frac{1}{2}m{v}_1^2$

Put values!

$KE=\frac{1}{2}\left(4g\right)v_2^2$

Then,

$v_1=2v_2$

So, $\frac{P_1}{P_2}=\frac{m_1{v}_1}{m_2{v}_2}=\frac{m\left(2v_2\right)}{m{v}_2}=\frac{2}{1}$

So, $Ratio=2:1$