A solar power pack stores 200 Wh of energy when fully charged.
PHYSICS · Multi-part · CBSE · Physics · Work and Energy · Work and Energy
Problem
A solar power pack stores 200 Wh of energy when fully charged.
(a) It operates a 25 W LED lamp for 3 h each night. If the energy conversion efficiency is 90 %, calculate the energy remaining in the pack after the lamp has been used for two consecutive nights.
(b) Using the energy left from part (a), the pack is then connected to a laptop that requires a constant 45 W. The efficiency remains 90 %. For how long, in minutes, can the laptop be powered?