Question

A force of 5N moves a body at rest with an accelaration of 3m/s2 for 4 sec. Find the work done by the force

Answer 1

Using 2nd eqn of motion:

$s = ut+ \frac{1}{2} at {}^{2}$here u=0

$s = \frac{1}{2} \times 3 \times 4 \times 4$

$s = 24m$

Then work done=

$force \times distance \: travelled$

=5 ×24

=120J

Answer 2

$<b><font color="orange" size="6"><marquee bgcolor="blue">Hey Buddy !</marquee></font>$

Here,
u = 0m/sec
s = ?
a = 3m/s2

$\therefore{}$
$s = ut + \frac{1}{2} a {t}^{2} \\ \\ = > s = 0(4) + \frac{1}{2} \times 3 \times {4}^{2} \\ \\ = s = \frac{1}{2} \times 3 \times 16 \\ \\ \fbox{= > s = 24m}$

$<b><font color="blue" size="6"><marquee bgcolor="orange">Now, Using formula :- Work = F × s</marquee></font>$
↓ ↓ ↓ ↓

Work Done = F × s

= 5N × 24

=120J

$<marquee> ︻╦̵̵̿╤─ ҉ - - - - - - </marquee>$