A boy held a ball in the air what force is he applying?

Which law represents the thermodynamic statement of the conservation of energy of a system? a. the fourth law b. the first law c. the second law d. the third law

Could someone me find the answer to this problem.

Determine the change in width a, height b, thickness t when a plate is subjected to the uniform distributed load and is made of material having modulus of elasticity e=230 gpa and poisson's ratio ν=1/3. given : a=400 mm and b= 300 mm also the uniformly distributed load in downward y direction of plate is 2 mn/m and in the positive x direction is 3 mn/m and t=20 mm