Question:
Suppose the bob of the previous problem has a speed of $1.4 \mathrm{~m} / \mathrm{s}$ when the string makes an angle of $0.20$ radian with the vertical. Find the tension at this instant. You can use $\cos \theta=1-\theta^{2} / 2$ and $\sin \theta=0$ for small $\theta$.
Solution:
