Answer: 200 watts
Step-by-step explanation:
Power is simply the ability to do work. In essence, power is workdone per unit time.
So, Power = Workdone / time taken 
In this case, time taken = 5 seconds
Workdone = 1000Joules
 
Power output = 1000 joules ➗ 5 second
 = 200 watts (power is measured in watts) 
Thus, your power output is 200 watts