Một con lắc lò xo dao động theo phương thẳng đứng với biên độ 3,6cm. Tỉ số độ lớn lực đàn hồi ở 2 biên gấp 4 lần nhau. Biết rằng lò xo luôn dãn trong quá trình dao động. Độ biến dạng của lò xo khi vật ở vị trí cân
bằng là:

Asolid round steel rod 6.25 mm in diameter and 375 mm long is rigidly bonded to the end of solid square brass rod 25 mm on a side and 300 mm long. the geometric axes of the bare are along the same line. an axial tensile force of 5.4 kn is applied at the extreme ends of the assembly. for steel e = 200 gpa and for brass e = 90 gpa. determine the total elongation for the assembly.

The first law of thermodynamics states that heat added to a system is neither created nor destroyed but is as it changes into other forms of energy.

First answer marked as brainiest which is the correct equation describing the first law of thermodynamics? a) when the internal energy of a system changes, it equals the amount of heat added plus the work done. b) when work is done by the piston, it is equal to the heat added plus the change in internal energy of the system. c) when heat is added to the system, it is equal to the amount of work done by the piston plus the change in internal energy of the system.