2700 Joules
Explanation:
Given variables are:
Workdone (w) = ?
Weight of sack (w) = 15N
Time taken (t) = 3 minutes
The standard unit of time is seconds, so convert 3 minutes to seconds
(If 1 minute = 60 seconds
3 minutes = 3 x 60 = 180 seconds)
Recall that work is done is when force is applied on an object over a distance
i.e Workdone = force x distance.
(However, the force acting on the sack of potatoes is weight)
Hence, workdone = weight x time
w = 15N x 180 seconds
w = 2700 J
thus, 2700 joules of work was done.