Water has a heat capacity of 4,184 j/kg*c. you have 2kg of water at a temperature of 98c. you want to raise the temperature to 100c. how much energy is needed to do this? 4,184j 16,736j 12,334j 9,445j

so easy. just google the electromagnetic waves and it’ll pop up.

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.