Q. The tube $A C$ forms a quarter circle in a vertical plane. The ball $B$ has an area of crosssection slightly smaller than that of the tube, and can move without friction through it. $B$ is placed at $A$ and displaced slightly. It will :

Work, Energy and Power Report Error

A

Always be in contact with the inner wall of the tube

B

Always be in contact with the outer wall of the tube

C

Initially be in contact with the inner wall and later with the outer wall

D

Initially be in contact with the outer wall and later with the inner wall.

Solution:

When the ball is released, we know that after an anglular displacement $\theta=\cos ^{-1}(-2 / 3)$ ball leaves contact with the inner wall of the tube and get in contact with the outer wall of the tube hence option (C) is correct.

Questions from Work, Energy and Power

1. The work done by a particle moving with a velocity of $0.7\, c$ (where c is the velocity of light) in empty space free of electromagnetic field and far away from all matter is:

Manipal 2008

2. The machine gun fires $240 \, $ bullets per minute. If the mass of each bullet is $10 \, g$ and the velocity of the bullets is $600 \, m \, s^{- 1}$ ,the power (in $kW$ )of the gun is

NTA Abhyas 2020

3. A body constrained to move along Z-axis of a coordinate system is subjected to a constant force $F$ given by $F =-\hat{i ⁡}+2\hat{j ⁡}+3\hat{k}N⁡$ where $\hat{i}$ , $\hat{j}$ and $\hat{k}$ are the unit vector along the X, Y and Z-axis of the system respectively. What is the work done by this force in moving the body a distance of $4 \, m$ along the Z-axis?

NTA Abhyas 2020

4. A particle of mass $m$ is moving in a circular path of constant radius $r$ such that its centripetal acceleration $a_{c}$ is varying with time $t$ as $a_{c}=k^{2} \, rt^{2}$ , where $k$ is a constant. The power delivered to the particle by the force acting on it is

NTA Abhyas 2020

5. A ball of mass $1\, kg$ collides with a wall with speed $8\, ms ^{-1}$ and rebounds on the same line with the same speed. If mass of the wall is taken as infinite, the work done by the ball on the wall is

Physics Most Viewed Questions

1. If $E$ and $G$ respectively denote energy and gravitational constant, then $\frac{ E }{ G }$ has the dimensions of:

NEET 2021 Physical World, Units and Measurements

2. The de Broglie wavelength of an electron moving with kinetic energy of $144 \,eV$ is nearly

NEET 2020 Dual Nature of Radiation and Matter

3. A car starts from rest and accelerates at $5\, m / s ^{2}$ At $t=4\, s$, a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at $t =6\, s$ ? (Take $\left. g =10\, m / s ^{2}\right)$

NEET 2021 Motion in a Straight Line

4. A wheel with $20$ metallic spokes each $1\, m$ long is rotated with a speed of $120\, rpm$ in a plane perpendicular to a magnetic field of $0.4\, G$. The induced emf between the axle and rim of the wheel will be, $(1 G = 10^{-4}\, T)$

NEET 2020 Electromagnetic Induction

5. A barometer is constructed using a liquid (density $= 760 \,kg/m^{3})$ What would be the height of the liquid column, when a mercury barometer reads $76\, cm$ ?
(density of mercury $= 13600 kg/m^{3})$

NEET 2020 Mechanical Properties of Fluids

Q. The tube $A C$ forms a quarter circle in a vertical plane. The ball $B$ has an area of crosssection slightly smaller than that of the tube, and can move without friction through it. $B$ is placed at $A$ and displaced slightly. It will :

Always be in contact with the inner wall of the tube

Always be in contact with the outer wall of the tube

Initially be in contact with the inner wall and later with the outer wall

Initially be in contact with the outer wall and later with the inner wall.

When the ball is released, we know that after an anglular displacement $\theta=\cos ^{-1}(-2 / 3)$ ball leaves contact with the inner wall of the tube and get in contact with the outer wall of the tube hence option (C) is correct.

Questions from Work, Energy and Power

1. The work done by a particle moving with a velocity of $0.7\, c$ (where c is the velocity of light) in empty space free of electromagnetic field and far away from all matter is:

2. The machine gun fires $240 \, $ bullets per minute. If the mass of each bullet is $10 \, g$ and the velocity of the bullets is $600 \, m \, s^{- 1}$ ,the power (in $kW$ )of the gun is

4. A particle of mass $m$ is moving in a circular path of constant radius $r$ such that its centripetal acceleration $a_{c}$ is varying with time $t$ as $a_{c}=k^{2} \, rt^{2}$ , where $k$ is a constant. The power delivered to the particle by the force acting on it is

5. A ball of mass $1\, kg$ collides with a wall with speed $8\, ms ^{-1}$ and rebounds on the same line with the same speed. If mass of the wall is taken as infinite, the work done by the ball on the wall is

Physics Most Viewed Questions

1. If $E$ and $G$ respectively denote energy and gravitational constant, then $\frac{ E }{ G }$ has the dimensions of:

2. The de Broglie wavelength of an electron moving with kinetic energy of $144 \,eV$ is nearly

3. A car starts from rest and accelerates at $5\, m / s ^{2}$ At $t=4\, s$, a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at $t =6\, s$ ? (Take $\left. g =10\, m / s ^{2}\right)$

4. A wheel with $20$ metallic spokes each $1\, m$ long is rotated with a speed of $120\, rpm$ in a plane perpendicular to a magnetic field of $0.4\, G$. The induced emf between the axle and rim of the wheel will be, $(1 G = 10^{-4}\, T)$

5. A barometer is constructed using a liquid (density $= 760 \,kg/m^{3})$ What would be the height of the liquid column, when a mercury barometer reads $76\, cm$ ? (density of mercury $= 13600 kg/m^{3})$

Latest Updates

5. A barometer is constructed using a liquid (density $= 760 \,kg/m^{3})$ What would be the height of the liquid column, when a mercury barometer reads $76\, cm$ ?
(density of mercury $= 13600 kg/m^{3})$