Angular momentum of a body is defined as the product of
1. Mass and angular velocity
2. Centripetal force and radius
3. Linear velocity and angular velocity
4. Moment of inertia and angular velocity
A rigid body rotates with an angular momentum L. If its rotational kinetic energy is made 4 times, its angular momentum will become
1. 4L
2. 16L
3.
4. 2L
The speed of a uniform spherical shell after rolling down an inclined plane of vertical height h from rest is:
1. \(\sqrt{\frac{10 g h}{7}}\)
2. \(\sqrt{\frac{6 g h}{5}}\)
3. \(\sqrt{\frac{4 g h}{5}}\)
4. \(\sqrt{2 g h}\)
A rigid body rotates about a fixed axis with a variable angular velocity equal to \(\alpha -\beta t\), at the time \(t\), where \(\alpha , \beta\) are constants. The angle through which it rotates before it stops is:
1. | \(\frac{\alpha^{2}}{2 \beta}\) | 2. | \(\frac{\alpha^{2} -\beta^{2}}{2 \alpha}\) |
3. | \(\frac{\alpha^{2} - \beta^{2}}{2 \beta}\) | 4. | \(\frac{\left(\alpha-\beta\right) \alpha}{2}\) |
Two masses \(m_1~\text{and}~m_2, ~m_1 >m_2\) are connected to the ends of massless rope and allowed to move as shown in the figure. The acceleration of the centre-of-mass assuming pulley is massless and frictionless, is:
1. \(\dfrac{m_{1}-m_{2}}{m_{1}+m_{2}} g\)
2. \(0\)
3. \(\left(\dfrac{m_1 -m_2}{m_1 + m_2 } \right)^2g \)
4. \(\left(\dfrac{m_1 +m_2}{m_1 - m_2 }\right)^2 g \)
Four particles of mass \(m_1 = 2m\), \(m_2=4m\), \(m_3 =m \), and \(m_4\) are placed at the four corners of a square. What should be the value of \(m_4\) so that the centre of mass of all the four particles is exactly at the centre of the square?
1. | \(2m\) | 2. | \(8m\) |
3. | \(6m\) | 4. | None of these |
For the uniform T shaped structure, with mass \(3~ \text M\), the moment of inertia about an axis normal to the plane and passing through O would be
1. \({ 2 \over 3} \text {MI}^2\)
2. \(\text {MI}^2\)
3. \({ MI^2 \over 3}\)
4. None of these
A uniform rod of mass m is bent into the form of a semicircle of radius R. The moment of inertia of the rod about an axis passing thorugh A and Perpendicular to the plane of paper is
1.
2.
3. 2
4.
A homogeneous disc of mass 2 kg and radius 15 cm is rotating about its axis (which is fixed) with an angular velocity of 4 rad/sec. The linear momentum Of the disc is
1. 1.2 kg m/sec
2. 1.0 kg m/sec
3. 0.6 kg m/sec
4. None of these