Question

The bob of a simple pendulum of length 1 m has mass 100 g and a speed of 1.4 m/s at the lowest point in its path. Find the tension in the string at this instant.

Answer 1

The tension in the string at this instant is 1.196 N

Explanation:

Step 1:

At absolute bottom, two forces are following up on the weave  

a) Tension in string upwards  

b) mg downwards.  

As it is moving along roundabout way subsequently

$\begin{equation}\begin{aligned}&T-m g=\frac{m v^{2}}{r}\\&T=m g+\frac{m v^{2}}{r}\end{aligned}$

Step 2:

Given that

Mass (m) = 100 g  

Converting gram to kilogram  

$\begin{equation}\frac{100}{1000}=0.1 \mathrm{kg}$

Mass = 0.1 kg

Speed (v) = 1.4 m/s

The length of bob of a simple pendulum is 1 m

i.e r= 1 m

g = 10 $m/s^{2}$ (The gravity of Earth)

Step 3:

Put the given values in above equation  

$\begin{equation}\begin{aligned}&\begin{aligned}T=& 0.1 \times 10+\frac{0.1 \times 1.4^{2}}{1} \\T &=1+\frac{0.1 \times 1.96}{1} \\T &=1+0.196\end{aligned}\\&T=1.196 \mathrm{N}\\\end{aligned}$

Answer 2

दीपक ऑफ अ सिंपल पेंडुलम ऑफ लैंड ऑफमास और इट्स बात है टेंशन ऑफ स्ट्रिंग एक्टिसिन स्टैंड