Question

Certain force acting on a 20 kg mass changes its velocity form 5 m/ s to 2 m/ s. Calculate the work done by the force

Answer 1

Hey Mate, Here's your answer

$mass \: of \: object(m) = 20 \: kg$

$initial \: velocity(u) = 5 \: m. {s}^{ - 2}$

$final \: velocity(v) = 2 \: m. {s}^{ - 2}$

$work \: done(w) = kinetic \: energy \\ = \frac{1}{2}m( {v}^{2} - {u}^{2} )$

$= \frac{1}{2} (20)( {2}^{2} - {5}^{2} )$

$= 10(4 - 25) = 10( - 21)$

$= 210 \: joules$

$( - ) \: sign \: indicates \: that \: work \: is \: in \: opp. \\ direction$

So Work done is 210 joules.

Hope this helps. Please mark my answer as Brainliest.

Answer 2

_/\_Hello mate__here is your answer--

_______________________

Given:-

Mass of the body = 20 kg

Initial velocity = 5 m/s

Final velocity = 2 m/s

To find:- work done by body

Solution:-

We know that,

work done =Change in kinetic energy

= 1/2mu^2 - 1/2mv^2

= 1/2m(u^2 − v^2)

= 1/2(20)(5^2 − 2^2)

= 10(25 − 4)

= 210 J

I hope, this will help you.☺

Thank you______❤

_________________________❤