Question

An arrow fired from a bow vertically upwards, attains a maximum height of $5m$ from the ground. If the mass of the arrow is $500g$, calculate the work done by the bow on the arrow (Take g = $10m{s}^{-1}$).

• A. $15J$
• B. $20J$
• C. $25J$
• D. $30J$

Answer 1

The correct option is C $25J$

Given: mass of the arrow, $m=500g=0.5kg$, height reached, $h=5m$, acceleration due to gravity, $g=10m{s}^{-2}$.
Let the work done by the bow be $W$.

Potential energy of arrow at the maximum height $=m\times g\times h=0.5\times 10\times 5=25J$ (As the bow is fired vertically upwards, at the maximum height only potential energy will exist)

Work done by the bow is equal to the potential energy of the arrow at the maximum height.
$\therefore W=25J$

Therefore, work done by the bow is $25J$.