Soy beans is the answer. the answer is soy beans :)
Answer:
Energy added to cold water, E1
E1 = m•Cp•ΔT = 6 x 4.187x(42-20) = 6x4.187x22
Energy lost by hot water, E2:
E2 = X(CpΔT) = X x 4.187 x (75-42) =X x 4.187 x 33
So, since E1 = E2
6x4.187x22 = X x 4.187 x 33
X = 6x22/33 = 4.0kg
So the mass of the hot water added to the 6kg of cold water is 4.0kg
By using the equation F=ma (Force = Mass*acceleration), the answer is 15,100 N for the first one and 1.25 m/s^2 for the second.