Answer:
Explanation:
We shall divide the stretch in two stage .
from .2 m to .25 m ( extension is .05 )
from .25 m to .3 m
force when length .2 m = 0
force when length .25 m = 17 x .05 = .85 N .
average force = (0 + .85) / 2
= .425 N
work done = average force x extension
= .425 x .05
= .02125 J .
from .25 m to .3 m
force when length .25 m = .85 N
force when length .3 m = 17 x .1 = 1.7 N .
average force = (1.7 + .85) / 2
= 1.275 N
work done = average force x extension
= 1.275 x .05
= .06375 J .