Question

The magnitude of a physical quantity is 8.5 Ns. The physical quantity is:

• A. force
• B. momentum
• C. pressure
• D. moment of force

Answer 1

The correct option is B

momentum

Explanation of correct option

Option (B) - momentum

1. As we know that momentum of the body is the product of mass and velocity.

$p=mv$

Where,

p = momentum of the body

m = mass of the object

v= velocity of the object

2. According to Newton's Second equation;

$F=ma$

where a is the acceleration of the object.

3. Force is equal to the rate of change in momentum. $\mathrm{F}=\frac{\mathrm{dp}}{\mathrm{dt}}\mathrm{where}\mathrm{p}\mathrm{is}\mathrm{momentum},\mathrm{F}\mathrm{is}\mathrm{force}$

4. Change in momentum = $F\times t$

5. Unit of force is newton and the unit of time is second.

6. So $Ns$is the unit of momentum.

Hence option (B) is correct.