Question

A force is applied on the body of mass 20kg moving with a velocity of 40m/s the body attains a velocity of 50m/s in 2 second calculate work donw

Answer 1

Work = f × s = m × a × s ( f = m×a)

a = ( v - u)/t = (50 - 40)/2 = 5 m/s

s = (v2 - u2)/2a = 50×50 -40×40/10 =2500-1600/10 = 90m

s = 90 m , a = 5 m/s and Given, m = 20kg

Work = m × a × s

work = 20 × 5 × 90

work = 9000 joul

work = 9kj.

I hope it will help uh.❤

Answer 2

Answer:

A force is applied on the body of mass 20kg moving with a velocity of 40m/s the body attains a velocity of 50m/s in 2 seconds, the work done is $9000Nm$

Explanation:

• The work done (W) is the product of the force (F) applied and displacement(d) of the body due to the applied force, that is

        $W=F.d$

• From Newton's second law $F=ma$

• The acceleration is the change in velocity with time $a=(v-u)/t$

• From the equation of motion, the distance moved by an accelerated body is      $s=ut+\frac{1}{2}at^{2}$

From the question, we have

mass of the body $m=20kg$

the initial velocity of the body $u=40m/s$

the final velocity $v=50m/s$

time taken for this change $t=2s$

⇒ the acceleration of the body

$a=\frac{50-40}{2} =10/2=5m/s^{2}$

now force on the body $F=20*5=100N$

the distance traveled $s=40*2+\frac{1}{2} *5*2^{2} =90m$

therefore required work done $W=100*90=9000Nm$