Bài 1.

Lực căng dây: \(T=\dfrac{P}{cosa}=\dfrac{10\cdot250\cdot10^{-3}}{cos45}=\dfrac{5\sqrt{2}}{2}\approx3,53N\)
Tốc độ góc:
\(tana=\dfrac{F_{ht}}{P}=\dfrac{\omega^2\cdot sina\cdot l.m}{mg}\Rightarrow\omega\approx5,318rad\)/s
Chu kì quay:
\(T=\dfrac{2\pi}{\omega}\approx1,18s\)
