A stone of mass m tied to the end of a string revolves in a vertical circle of radius R. The net forces at the lowest and highest points of the circle directed vertically downwards are Lowest Point Highest Point (a) mg-T1 mg+T2 (b) mg +T1 mg-T2 (c) mg+T1 -((mv12/R)) mg-T2 +((mv22/R)) (d) mg-T1 -((mv12/R)) mg+T2 +((mv22/R)) T1 and v1 denote the tension and speed at the lowest point. T2 and v2 denote corresponding values at the highest point.

Question

A stone of mass m tied to the end of a string revolves in a vertical circle of radius R. The net forces at the lowest and highest points of the circle directed vertically downwards are Lowest Point Highest Point (a) mg-T1 mg+T2 (b) mg +T1 mg-T2 (c) mg+T1 -((mv12/R)) mg-T2 +((mv22/R)) (d) mg-T1 -((mv12/R)) mg+T2 +((mv22/R)) T1 and v1 denote the tension and speed at the lowest point. T2 and v2 denote corresponding values at the highest point. (A) a (B) b (C) c (D) d

Tardigrade Admin · Accepted Answer

At the lowest point, mg acts downwards and T1 upwards so that net force =mg -T1. At the highest point, both mg and T2 act downwards so that net force=mg +T2.

	Lowest Point	Highest Point
(a)	$m g - T_{1}$	$m g + T_{2}$
(b)	$m g + T_{1}$	$m g - T_{2}$
(c)	$m g + T_{1}$ $- (\frac{m v _{1}^{2}}{R})$	$m g - T_{2}$ $+ (\frac{m v _{2}^{2}}{R})$
(d)	$m g - T_{1}$ $- (\frac{m v _{1}^{2}}{R})$	$m g + T_{2}$ $+ (\frac{m v _{2}^{2}}{R})$

a

b

c

d

At the lowest point, mg acts downwards and T1​ upwards so that net force =mg −T1​. At the highest point, both mg and T2​ act downwards so that net force=mg +T2​.

At the lowest point, mg acts downwards and $T_{1}$
upwards so that net force $= m g$ $- T_{1}$ .
At the highest point, both $m g$ and $T_{2}$ act downwards so that net force $= m g$ $+ T_{2} .$