A machine does 1000 J of work in 3.5 minutes (210 seconds). What is
the power output of this machine?

4.76 watts

Explanation:

Work = 1000 J

Time = 3.5 minutes (210 seconds)

Since the SI unit of time is seconds, 210 seconds will be used in calculation.

Power output of the machine = ?

Recall that power is the rate of doing work. Thus, power is Workdone divided by time taken.

i.e Power = (work/time)

Power = 1000J/210seconds

Power = 4.76 watts

Thus, the power output of the machine is 4.76 watts

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27