A large coal fired power plant has an efficiency of 45% and produces net 1,500 MW of electricity. Coal releases 25 000 kJ/kg as it burns so how much coal is used per hour

133.33 kg/s

Explanation:

Calculation for how much coal is used per hour

Using this formula

Coal used per hour=(Net MW of electricity*1,000 / Efficiency%* Released kJ/kg

Let plug in the formula

Coal used per hour=1,500 MW*1,000/0.45*25,000 kJ/kg

Coal used per hour=1,500,000/11,250kJ/kg

Coal used per hour=133.33 kg/s

Therefore how much coal is used per hour is 133.33 kg/s

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s