Question

mohan lifts a cell phone to height of 1 metre and takes 1 second to do this .after lowering the cell phone he lifts it to 2 metre in 2 second .has he generated more power in doing the second task?​

Answer 1

Explanation:

Let,

m = mass of the cell phone

h = height rised

g = acceleration due to gravity

___

work = mgh

$w \: = mg \times 1 \\ w = mg$

Now ,

Now , Calculating the power delivered of both

$power \: deliver \: = \: \frac{work \: done}{time} \\ \: \: \: \: \: = \frac{mg}{1} \\ \: \: \: \: = mg$

Work done on lifting cellphone by 2 phone

$\: \: \: \: \: \: = mg \: \times 2 \\ \: \: \: \: \: \: \: = 2mg$

Now power delivered

$power \: delivered \: = \frac{work \: done \: }{time} \\ \: \: \: \: \: \: = \frac{2mg}{2}$

= mg

So in both cases power delivered is same

Answer 2

mohan lifts a cell phone to height of 1 metre and takes 1 second to do this .after lowering the cell phone he lifts it to 2 metre in 2 second .has he generated more power in doing the second task?

Answer:-

Let, mass of cellphone be m kgWork done

(W) by Mohan = mghwhere, h = height at

which cellphone is raised andg =

acceleration due to gravity=> W = mg X 1 =

mgPower delivered =Work done / time =

mg / 1 = mgWork done to lift cellphone by 2

m = mg X 2 = 2mgPower delivered =Work

done / time = 2mg / 2 = mgSo, in both cases

power delivered by Mohan is same____.

#khushu__☺️