Question

The physical quantity impulse has the same dimensions as that of

• A. Force
• B. Power
• C. Energy
• D. Momentum

Answer 1

The correct option is D

Momentum

Option (d) is correct.

By definition, Impulse = change in momentum.

According to dimensional analysis, two quantities can be equated only if they have the same dimensions.

So, impulse has the same dimension as momentum.

Momentum , $P=mv$; where $m$ = mass and $v$=velocity

Dimension of momentum,

$\begin{array}{rcl}\left[P\right]& =& \left[m\right]\left[v\right]\\ & =& ML{T}^{-1}\end{array}$

Hence, the dimension of impulse is $ML{T}^{-1}$.

Incorrect options:

(A) Force:

Dimension of Force : $ML{T}^{-2}$

(B) Power:

Dimension of Power : $M{L}^2{T}^{-3}$

(C) Energy

Dimension of energy: $M{L}^2{T}^{-2}$

Thus, impulse has the same dimensions as that momentum.