Question

for work to be performed energy must be ?

Answer 1

Answer:

yes

Explanation:

Energy is necessary to be performing any work. Because for every living things energy is very important.

Answer 2

from 2nd law of thermodynamics ,

i.e dQ=dU + dW( work done)

where dU=nCvdT. in isothermal process (dT=0) whole of your energy is converted to work

in adiabatic process (dQ=0) so work is done at cost of internal energy of system ..

from mechanics,

W=F×s cos (theta)

it shows if you applied force perpendicular( theta =0 ) to the surface no work is done i.e mechanical energy isnot converted to work.