How many joules of energy does a 100-watt light bulb use per hour? How fast would a 70-kg person have to run to have that amount of kinetic energy?
Solution 49E Introduction The power of the bulb and the time is given, we have to calculate the total energy. Then using the above calculated energy we can calculated the velocity of since the mass of the person. Step 1 The power of the bulb is P = 100 W Time of the operation is t = 1 h = 3600 s 5 Hence the energy used by bulb in one hour is E = (100 W)(3600 s) = 3.6 × 10 J .