Question

If the units of force and that of length are doubled the unit of energy will be

Answer 1

Let original energy be =E1=f.s
 Then, new energy=E2 = 2f.2s= 4f.s= 4E1
Hence, energy is increased by 4 times. 

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Answer 2

Answer: The unit of energy will be four times.

Explanation:

Given that,

If the units of force and that of length are doubled

We know that,

The energy is the work done and work done is the product of force and length.

$E = W = F\times l$

The unit of energy is

$E = MLT^{-2}\times L$

$E = ML^2T^{-2}$

If the unit of force and length are double then ,

$E' = 2(MLT^{-2})\times 2L$

$E' = 4(ML^2T^{-2})$

$E' = 4 E$

Hence, The unit of energy will be four times.