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 ▸Why do astronauts feel weightless while in orbit?
Sophia (mass 47Kg) is travelling to the right with a velocity of 7.2m/s and Neesha (mass 68Kg) is travelling to the left with a velocity 4.8m/s. When they meet, they hold hands and travel off together. Give their final velocity and direction
Describe the difference between reflection and refraction (assume the mediums have smooth surfaces)
Compare the advantages and disadvantages of the two methods of generating electricity (figure 1 in answer):