Một vật dao động điều hòa theo phương trình x=6cos(4πt),vật tốc của vật tại thời điểm t=7,5s

Which graph best represents the relationship between the electric current and the rate at which a magnet is turning inside an electric generator?

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.

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