Question

if we lift the Cody of mass 7 kg vertically upwards to a height of 10 mm. Calculate the work done in lifting the body​

Answer 1

Given:-

Mass of Body = 7kg

Initial Velocity = 0m/s ( As it was at rest )

Acceleration = + 10m/s²

Distance Travelled = 10m

To Find:-

The Force required to lift a body

Formulae used:-

P.E = mgh

w = F × s

Where,

P.E = Potential Energy

m = Mass

g = Gravitation

h = Height

w = Work Done

F = Force

s = Distance

How To Solve ?

Here, given is not enough to use any Newton's Equation.

So, we will use the Equation of G.P.E. where we will find the Work done.

Then we will use the Formulae of work done.

Now,

→ P.E = mgh

→ P.E = 7 × 10 × 10

→ P.E = 700J.

Hence, The energy need to lift the body is 700J

Therefore,

→ W = F × S

→ 700 = F × 10

→ F = 700/10

→ F = 70N.

Hence, The Force required to lift the body is 70N.

Answer 2

Answer:

work done in lifting the body vertically upwards of mass 7 kg and height 10mm is mgh,

work done = mgh = 7*10*0.01= 0.7joules