Question

A force produces an acceleration of $5.0cm{s}^{-2}$ when it acts on a body of mass $20g$. The force in Newton is:

1 dyne = $1gcm{s}^{-2}$

• A. $2\times {10}^{-3}$
• B. $4\times {10}^{-3}$
• C. $1.0\times {10}^{-3}$
• D. $5\times {10}^{-3}$

Answer 1

The correct option is C

$1.0\times {10}^{-3}$

F= ma = $20\times 5=100dyne$.
$But1dyne={10}^{-5}N$
$\therefore F=100\times {10}^{-5}N=1\times {10}^{-3}N$