Calculating Energy Using Power and Time

What is the unit of measurement for power?

• Joules
• Watts
• Voltage
• Calories

The equation that links energy power and time

• Energy = Power / Time
• Energy = Time / Power
• Power = Energy / Time
• Energy = Power x Time

How much energy does a 150W appliance transfer in 10s?

Energy = power x time

• 2500 J

• 1500 J

• 2000 J

• 1000 Jo

A lamp has a 120 W power rating. It is left on for 30 seconds. How much energy did it use in kJ?

Energy = power x time

• 3600 kJ

• 3.6 kJ

• 450 kJ

• 20 kJ

How much energy does a 300W appliance transfer in 2 minutes?

Energy = power x time

HINT there are 60s in 1 minute