Calculate the energy needed to heat 4 kg of water from 25 degrees c to 45 degrees c

1 cal/g °C) x (4000 g) x (45 - 25)°C = 80000 cal = 80 kcal

So answer (a)

80

the answer is ampere

the ampere is used to measure electricity. an ampere is a unit of electric current equal. a unit of measure for the flow of current in a circuit. one ampere is the amount of current flow provided when one volt of electrical pressure is applied against one ohm of resistance.

conservation of mass

mass before something happens = mass afterwards