The formula for calculating power is expressed as
P = IV
where
P = power
I = current
V = voltage
From the information given,
V = 80
I = 5
Thus,
Power = 5 x 80 = 400
The formula for calculating energy is expressed as
Energy = power x time
Given that time = 2.5 minute, we would convert it to seconds
Recall,
1 minute = 60 seconds
2.5 minutes = 2.5 x 60 = 150 seconds
Thus,
Energy = 400 x 150
Energy = 60000 J