Question

When a bullet is fired from a rifle its momentum become 20 kg m/s. If the velocity of the bullet is 1000m/s what will be its mass?

Answer 1

$\bf \huge{Answer} \\ \\ \sf \: momentum \: = mass \times velocity \\ \\ \sf \: mass \: = \frac{momentum}{velocity} \\ \\ \sf \: mass \: \: = \frac{20}{1000} \\ \\ \sf \: mass = 0.002 \: kg$

Answer 2

Given:

Momentum of bullet is 20 kg.m/s

Velocity of bullet=1000m/s

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To find:

Mass of bullet

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Solution:

We have formula for momentum:

$\large\boxed{\sf\normalsize\maltese\;\; P=Vm}$

$\bf {Here}\begin{cases}\sf P=momentum\\\sf V=Velocity\\\sf m=mass\end{cases}$

Now substituting given values in the formula.

$\implies\sf 20kg.m/s=(1000 m/s)(Mass)$

Now transportation of LHS and RHS.

$\implies\sf \dfrac{20kg.m/s}{1000m/s}=Mass$

$\implies\sf \dfrac{20kg}{1000}=Mass$

Now converting Kg into grams.

$\implies\sf \dfrac{20\times 1000 g}{1000}=Mass$

1000 will be cancelled from Nr. and Dn., We get:

$\implies\sf \dfrac{20 g}{1}=Mass$

$\underline{\boxed{\implies\bf 20 g=Mass}}$

So the required mass of bullet is 20 grams.

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