A boy is hanging from branch of a tree as shown. Angle between his arm, for tension to be maximum&nb

English

Gujarati

Hindi

4-1.Newton's Laws of Motion

medium

A boy is hanging from branch of a tree as shown. Angle between his arm, for tension to be maximum in arms must be ............ $^o$

A

$60$

B

$74$

C

$90$

D

$120$

Solution

$2 \mathrm{T} \cos \frac{\theta}{2}=\mathrm{Mg}$ for equillibrium

$\mathrm{T}=\frac{\mathrm{Mg}}{2 \cos \frac{\theta}{2}}$

for $T$ to be maximum cos $\frac{\theta}{2}$ must be minimum so

$\frac{\theta}{2}$ must be maximum

Standard 11

Physics

Share

Similar Questions

A block of weight $W$ is supported by three strings as shown in figure. Which of the following relations is true for tension in the strings? (Here $T_1, T_2$ and $T_3$ are the tension in the strings $A, B$ and $C$ respectively)

medium

For given systen ${\theta _1}$ ……. $^o$

medium

In the system shown in the adjoining figure, the tension $T_2$ is

easy

A piece of wire is bent in the shape of a parabola $y=k x^2$ ( $y$-axis vertical) with a bead of mass $m$ on it. The bead can slide on the wire without friction. It stays at the lowest point of the parabola when the wire is at rest. The wire is now accelerated parallel to the $x$-axis with a constant acceleration $\alpha$. The distance of the new equilibrium position of the bead, where the bead can stay at rest with respect to the wire, from the $y$-axis is

hard

(IIT-2009)

Give the magnitude and direction of the net force acting on

$(a)$ a drop of rain falling down with a constant speed,

$(b)$ a cork of mass $10\; g$ floating on water,

$(c)$ a kite skillfully held stationary in the sky,

$(d)$ a car moving with a constant velocity of $30\; km/h$ on a rough road,

$(e)$ a high-speed electron in space far from all material objects, and free of electric and magnetic fields.

medium