A 6.0W bulb is connected to a source of 480J of energy. Assuming the system is 100% efficient, and the bulb runs at full power, how long can it stay lit?

  • Bulb power = 6.0W - Energy provided = 480J - Use equation P = E / t (Power = energy/time) where power is in watts, energy is in joules, and time is in seconds - Rearrange the equation to give t = E / P (time = energy/power) to find the time in seconds - Plug in the values to give t = 480/6 = 80 - Therefore time = 80 seconds.
LW

Related Physics GCSE answers

All answers ▸

Alice and Bob are sat on a seesaw. The seesaw is in static equilibrium. Alice weighs 500N and is sat 0.5m to the left of the pivot. If Bob weighs 800N, how far from the pivot on the right is he sat? What happens if Bob moves closer to the pivot?


A 2 kW electric fire is switched on for 30 minutes. How many Units of electricity does it use?


Find the period of a wave given that it has a speed of 200m/s and a wavelength of 2m


What does the term terminal velocity mean?