Question

The length of the string of a conical pendulum is $90cm$ and its bob moves in a circular path of radius $25cm$. What is the tension in the string if the bob has mass $150g$? (in $N$)

• A. $1.32$
  
• B. $1.96$
  
• C. $1.53$
  
• D. $1.23$
  

Answer 1

The correct option is C $1.53$

$m=150g=0.150kg,r=25cm=0.25m,h=90cm=0.90m$
The tension in conical pendulum is
$T=mg\sqrt{(1+\frac{r^2}{h^2})}=0.150\ast 9.8\sqrt{(1+\frac{{0.25}^2}{{0.90}^2})}=1.53N$