: Hai quả cầu m1 = 200g, m2= 100g treo cạnh nhau bằng hai dây giống nhau. Nâng quả cầu m1 lên h = 4,5 m rồi thả nhẹ. a. Tính vận tốc m1 lúc sắp va chạm vào m2.
b. Tính vận tốc hai quả cầu sau va chạm, biết va chạm giữa chúng là va chạm mềm.
c. Sau va chạm, hai quả cầu được nâng lên độ cao cực đại bằng bao nhiêu?

In science and physics what is the standard unit of measure for speed?

A47.2 g block of copper whose temperature is 480 k is placed in an insulating box with a 91.8 g block of lead whose temperature is 200 k. (a) what is the equilibrium temperature of the two-block system? (b) what is the change in the internal energy of the two-block system between the initial state and the equilibrium state? (c) what is the change in the entropy of the two-block system? the heat capacities of copper and lead are 386 j/kg·k and 128 j/kg·k, respectively.

Suppose a force of 60 n is required to stretch and hold a spring 0.1 m from its equilibrium position. a. assuming the spring obeys hooke's law, find the spring constant k. b. how much work is required to compress the spring 0.5 m from its equilibrium position? c. how much work is required to stretch the spring 0.6 m from its equilibrium position? d. how much additional work is required to stretch the spring 0.1 m if it has already been stretched 0.1 m from its equilibrium? a. kequals 600