A block is dragged on a smooth plane with help of a rope which moves with a velocity v as shown in f

English

Gujarati

Hindi

4-1.Newton's Laws of Motion

easy

A block is dragged on a smooth plane with the help of a rope which moves with a velocity $v$ as shown in figure. The horizontal velocity of the block is

A

$v$

B

$\frac{v}{{\sin \,\theta }}$

C

$v\, sin\,\theta$

D

$\frac{v}{{\cos \,\theta }}$

Solution

$x^{2}+h^{2}=y^{2}$

$\Rightarrow 2 \mathrm{x} \frac{\mathrm{dx}}{\mathrm{dt}}+0=2 \mathrm{y} \frac{\mathrm{dy}}{\mathrm{dt}}$

$\Rightarrow \frac{\mathrm{dx}}{\mathrm{dt}}=\frac{\mathrm{y}}{\mathrm{x}} \cdot \mathrm{v}=\frac{\mathrm{v}}{\sin \theta}$

Standard 11

Physics

Share

Similar Questions

If all the pulleys are massless and string is ideal, find the reading of spring balance

hard

The velocities of $A$ and $B$ are marked in the figure. The velocity of block $C$ is ……… $m/s$ (assume that the pulleys are ideal and string inextensible)

normal

A block of mass $2 M$ is attached to a massless spring with spring-constant $k$. This block is connected to two other blocks of masses $M$ and $2 M$ using two massless pulleys and strings. The accelerations of the blocks are $a_1, a_2$ and $a_3$ as shown in figure. The system is released from rest with the spring in its unstretched state. The maximum extension of the spring is $x _0$. Which of the following option($s$) is/are correct? [g is the acceleration due to gravity. Neglect friction]

normal

(IIT-2019)

The acceleration of the $2\,kg$ block if the free end of string is pulled with a force of $20\,N$ as shown is

medium

Figure shows a boy on a horizontal platform $A$ on a smooth horizontal surface, holding a rope attached to a box $B$ . Boy pulls the rope with a constant force of $50\ N$ . (boy does not slip over the platform). The combined mass of platform $A$ and boy is $250\ kg$ and that of box $B$ is $500\ kg$ . The velocity of $A$ relative to the box $B$ , $5\ s$ after the boy on $A$ begins to pull the rope, will be ………… $m/s$

hard