Question

The resistive force $F$ acting on a ball of radius $r$ moving with velocity $v$ is given by
$F=K r v$
The dimensional formula of $K$ is

• A. $[MLT]$
• B. $\left[ M ^{-1} LT \right]$
• C. $\left[ M ^{-1} L ^{-1} T \right]$
• D. $\left[ ML ^{-1} T ^{-1}\right]$

Answer 1

Answer: (D)

As $F=K r v$
$[K]=\frac{[F]}{[r][v]}=\frac{ MLT ^{-2}}{ LLT ^{-1}}= ML ^{-1} T ^{-1}$