# physics-energy conservation

posted by
**Emma**
.

a mordern power station,or, more correctly, an energy station, converts heat energy into electrical energy at an efficiency od 50% if the station produces electrical energy at a rate of 1.00GW from burning coal, calculate the mass of coal it burns each day. the coal it uses produces 25.0MJ of heat per kg when it burns completely.

i knows that 1.00W =1.00Js-

and i forgot about the formula...can someone help?

Energy= efficiency*power*time

Remember that a watt is a joule/second, so time has to be in seconds (seconds in a day...)