05. Rotational Motion and Rotational Energy
Rotational Motion

150296 A ball of radius \(\mathrm{R}\) rolls without slipping. Find the fraction of total energy associated with its rotational energy, if the radius of the gyration of the ball about an axis passing through its centre of mass is \(K\).

1 ) \(\frac{K^{2}}{\left(K^{2}+R^{2}\right)}\)
2 ) \(\frac{\mathrm{R}^{2}}{\left(\mathrm{~K}^{2}+\mathrm{R}^{2}\right)}\)
3 ) \(\frac{\left(\mathrm{K}^{2}+\mathrm{R}^{2}\right)}{\mathrm{R}^{2}}\)
4 ) \(\frac{\mathrm{K}^{2}}{\mathrm{R}^{2}}\)
Rotational Motion

150297 A sphere is rolling on a horizontal surface without slipping. The ratio of the rotational K.E. to the total kinetic energy of the sphere is

1 ) \(\frac{2}{5}\)
2 ) \(\frac{2}{7}\)
3 ) \(\frac{5}{7}\)
4 ) \(\frac{3}{7}\)
Rotational Motion

150298 The moment of inertia of a body about a given axis is \(1.2 \mathrm{~kg} \mathrm{~m}^{2}\). Initially the body is at rest. In order to produce a rotational kinetic energy of \(1500 \mathrm{~J}\), an angular acceleration of \(25 \mathrm{rad} / \mathrm{s}^{2}\) must be applied about that axis for a duration of-

1 ) \(4 \mathrm{~s}\)
2 ) \(2 \mathrm{~s}\)
3 ) \(8 \mathrm{~s}\)
4 ) \(10 \mathrm{~s}\)
Rotational Motion

150299 The angular momentum of a wheel having a rotational inertia of \(0.2 \mathrm{~kg} \mathrm{~m}^{2}\) about its symmetric axis decreases from 4 to \(2 \mathrm{~kg} \mathrm{~m}^{2} \mathrm{~s}^{-1}\) in 4s. The average power of the wheel is

1 ) \(7.5 \mathrm{~W}\)
2 ) \(15 \mathrm{~W}\)
3 ) \(5 \mathrm{~W}\)
4 ) \(12 \mathrm{~W}\)
Rotational Motion

150300 A circular disc of weight \(500 \mathrm{~N}\) and of radius 1 \(m\) is started from rest by a constant horizontal force of \(25 \mathrm{~N}\) applied tangentially to the disc. The kinetic energy of the disc after time \(t=2\) [Acceleration due to gravity \(=\mathbf{1 0} \mathbf{~ m s}^{-2}\) ]

1 \(50 \mathrm{~J}\)
2 \(75 \mathrm{~J}\)
3 \(100 \mathrm{~J}\)
4 \(25 \mathrm{~J}\)
Rotational Motion

150296 A ball of radius \(\mathrm{R}\) rolls without slipping. Find the fraction of total energy associated with its rotational energy, if the radius of the gyration of the ball about an axis passing through its centre of mass is \(K\).

1 ) \(\frac{K^{2}}{\left(K^{2}+R^{2}\right)}\)
2 ) \(\frac{\mathrm{R}^{2}}{\left(\mathrm{~K}^{2}+\mathrm{R}^{2}\right)}\)
3 ) \(\frac{\left(\mathrm{K}^{2}+\mathrm{R}^{2}\right)}{\mathrm{R}^{2}}\)
4 ) \(\frac{\mathrm{K}^{2}}{\mathrm{R}^{2}}\)
Rotational Motion

150297 A sphere is rolling on a horizontal surface without slipping. The ratio of the rotational K.E. to the total kinetic energy of the sphere is

1 ) \(\frac{2}{5}\)
2 ) \(\frac{2}{7}\)
3 ) \(\frac{5}{7}\)
4 ) \(\frac{3}{7}\)
Rotational Motion

150298 The moment of inertia of a body about a given axis is \(1.2 \mathrm{~kg} \mathrm{~m}^{2}\). Initially the body is at rest. In order to produce a rotational kinetic energy of \(1500 \mathrm{~J}\), an angular acceleration of \(25 \mathrm{rad} / \mathrm{s}^{2}\) must be applied about that axis for a duration of-

1 ) \(4 \mathrm{~s}\)
2 ) \(2 \mathrm{~s}\)
3 ) \(8 \mathrm{~s}\)
4 ) \(10 \mathrm{~s}\)
Rotational Motion

150299 The angular momentum of a wheel having a rotational inertia of \(0.2 \mathrm{~kg} \mathrm{~m}^{2}\) about its symmetric axis decreases from 4 to \(2 \mathrm{~kg} \mathrm{~m}^{2} \mathrm{~s}^{-1}\) in 4s. The average power of the wheel is

1 ) \(7.5 \mathrm{~W}\)
2 ) \(15 \mathrm{~W}\)
3 ) \(5 \mathrm{~W}\)
4 ) \(12 \mathrm{~W}\)
Rotational Motion

150300 A circular disc of weight \(500 \mathrm{~N}\) and of radius 1 \(m\) is started from rest by a constant horizontal force of \(25 \mathrm{~N}\) applied tangentially to the disc. The kinetic energy of the disc after time \(t=2\) [Acceleration due to gravity \(=\mathbf{1 0} \mathbf{~ m s}^{-2}\) ]

1 \(50 \mathrm{~J}\)
2 \(75 \mathrm{~J}\)
3 \(100 \mathrm{~J}\)
4 \(25 \mathrm{~J}\)
Rotational Motion

150296 A ball of radius \(\mathrm{R}\) rolls without slipping. Find the fraction of total energy associated with its rotational energy, if the radius of the gyration of the ball about an axis passing through its centre of mass is \(K\).

1 ) \(\frac{K^{2}}{\left(K^{2}+R^{2}\right)}\)
2 ) \(\frac{\mathrm{R}^{2}}{\left(\mathrm{~K}^{2}+\mathrm{R}^{2}\right)}\)
3 ) \(\frac{\left(\mathrm{K}^{2}+\mathrm{R}^{2}\right)}{\mathrm{R}^{2}}\)
4 ) \(\frac{\mathrm{K}^{2}}{\mathrm{R}^{2}}\)
Rotational Motion

150297 A sphere is rolling on a horizontal surface without slipping. The ratio of the rotational K.E. to the total kinetic energy of the sphere is

1 ) \(\frac{2}{5}\)
2 ) \(\frac{2}{7}\)
3 ) \(\frac{5}{7}\)
4 ) \(\frac{3}{7}\)
Rotational Motion

150298 The moment of inertia of a body about a given axis is \(1.2 \mathrm{~kg} \mathrm{~m}^{2}\). Initially the body is at rest. In order to produce a rotational kinetic energy of \(1500 \mathrm{~J}\), an angular acceleration of \(25 \mathrm{rad} / \mathrm{s}^{2}\) must be applied about that axis for a duration of-

1 ) \(4 \mathrm{~s}\)
2 ) \(2 \mathrm{~s}\)
3 ) \(8 \mathrm{~s}\)
4 ) \(10 \mathrm{~s}\)
Rotational Motion

150299 The angular momentum of a wheel having a rotational inertia of \(0.2 \mathrm{~kg} \mathrm{~m}^{2}\) about its symmetric axis decreases from 4 to \(2 \mathrm{~kg} \mathrm{~m}^{2} \mathrm{~s}^{-1}\) in 4s. The average power of the wheel is

1 ) \(7.5 \mathrm{~W}\)
2 ) \(15 \mathrm{~W}\)
3 ) \(5 \mathrm{~W}\)
4 ) \(12 \mathrm{~W}\)
Rotational Motion

150300 A circular disc of weight \(500 \mathrm{~N}\) and of radius 1 \(m\) is started from rest by a constant horizontal force of \(25 \mathrm{~N}\) applied tangentially to the disc. The kinetic energy of the disc after time \(t=2\) [Acceleration due to gravity \(=\mathbf{1 0} \mathbf{~ m s}^{-2}\) ]

1 \(50 \mathrm{~J}\)
2 \(75 \mathrm{~J}\)
3 \(100 \mathrm{~J}\)
4 \(25 \mathrm{~J}\)
NEET Test Series from KOTA - 10 Papers In MS WORD WhatsApp Here
Rotational Motion

150296 A ball of radius \(\mathrm{R}\) rolls without slipping. Find the fraction of total energy associated with its rotational energy, if the radius of the gyration of the ball about an axis passing through its centre of mass is \(K\).

1 ) \(\frac{K^{2}}{\left(K^{2}+R^{2}\right)}\)
2 ) \(\frac{\mathrm{R}^{2}}{\left(\mathrm{~K}^{2}+\mathrm{R}^{2}\right)}\)
3 ) \(\frac{\left(\mathrm{K}^{2}+\mathrm{R}^{2}\right)}{\mathrm{R}^{2}}\)
4 ) \(\frac{\mathrm{K}^{2}}{\mathrm{R}^{2}}\)
Rotational Motion

150297 A sphere is rolling on a horizontal surface without slipping. The ratio of the rotational K.E. to the total kinetic energy of the sphere is

1 ) \(\frac{2}{5}\)
2 ) \(\frac{2}{7}\)
3 ) \(\frac{5}{7}\)
4 ) \(\frac{3}{7}\)
Rotational Motion

150298 The moment of inertia of a body about a given axis is \(1.2 \mathrm{~kg} \mathrm{~m}^{2}\). Initially the body is at rest. In order to produce a rotational kinetic energy of \(1500 \mathrm{~J}\), an angular acceleration of \(25 \mathrm{rad} / \mathrm{s}^{2}\) must be applied about that axis for a duration of-

1 ) \(4 \mathrm{~s}\)
2 ) \(2 \mathrm{~s}\)
3 ) \(8 \mathrm{~s}\)
4 ) \(10 \mathrm{~s}\)
Rotational Motion

150299 The angular momentum of a wheel having a rotational inertia of \(0.2 \mathrm{~kg} \mathrm{~m}^{2}\) about its symmetric axis decreases from 4 to \(2 \mathrm{~kg} \mathrm{~m}^{2} \mathrm{~s}^{-1}\) in 4s. The average power of the wheel is

1 ) \(7.5 \mathrm{~W}\)
2 ) \(15 \mathrm{~W}\)
3 ) \(5 \mathrm{~W}\)
4 ) \(12 \mathrm{~W}\)
Rotational Motion

150300 A circular disc of weight \(500 \mathrm{~N}\) and of radius 1 \(m\) is started from rest by a constant horizontal force of \(25 \mathrm{~N}\) applied tangentially to the disc. The kinetic energy of the disc after time \(t=2\) [Acceleration due to gravity \(=\mathbf{1 0} \mathbf{~ m s}^{-2}\) ]

1 \(50 \mathrm{~J}\)
2 \(75 \mathrm{~J}\)
3 \(100 \mathrm{~J}\)
4 \(25 \mathrm{~J}\)
Rotational Motion

150296 A ball of radius \(\mathrm{R}\) rolls without slipping. Find the fraction of total energy associated with its rotational energy, if the radius of the gyration of the ball about an axis passing through its centre of mass is \(K\).

1 ) \(\frac{K^{2}}{\left(K^{2}+R^{2}\right)}\)
2 ) \(\frac{\mathrm{R}^{2}}{\left(\mathrm{~K}^{2}+\mathrm{R}^{2}\right)}\)
3 ) \(\frac{\left(\mathrm{K}^{2}+\mathrm{R}^{2}\right)}{\mathrm{R}^{2}}\)
4 ) \(\frac{\mathrm{K}^{2}}{\mathrm{R}^{2}}\)
Rotational Motion

150297 A sphere is rolling on a horizontal surface without slipping. The ratio of the rotational K.E. to the total kinetic energy of the sphere is

1 ) \(\frac{2}{5}\)
2 ) \(\frac{2}{7}\)
3 ) \(\frac{5}{7}\)
4 ) \(\frac{3}{7}\)
Rotational Motion

150298 The moment of inertia of a body about a given axis is \(1.2 \mathrm{~kg} \mathrm{~m}^{2}\). Initially the body is at rest. In order to produce a rotational kinetic energy of \(1500 \mathrm{~J}\), an angular acceleration of \(25 \mathrm{rad} / \mathrm{s}^{2}\) must be applied about that axis for a duration of-

1 ) \(4 \mathrm{~s}\)
2 ) \(2 \mathrm{~s}\)
3 ) \(8 \mathrm{~s}\)
4 ) \(10 \mathrm{~s}\)
Rotational Motion

150299 The angular momentum of a wheel having a rotational inertia of \(0.2 \mathrm{~kg} \mathrm{~m}^{2}\) about its symmetric axis decreases from 4 to \(2 \mathrm{~kg} \mathrm{~m}^{2} \mathrm{~s}^{-1}\) in 4s. The average power of the wheel is

1 ) \(7.5 \mathrm{~W}\)
2 ) \(15 \mathrm{~W}\)
3 ) \(5 \mathrm{~W}\)
4 ) \(12 \mathrm{~W}\)
Rotational Motion

150300 A circular disc of weight \(500 \mathrm{~N}\) and of radius 1 \(m\) is started from rest by a constant horizontal force of \(25 \mathrm{~N}\) applied tangentially to the disc. The kinetic energy of the disc after time \(t=2\) [Acceleration due to gravity \(=\mathbf{1 0} \mathbf{~ m s}^{-2}\) ]

1 \(50 \mathrm{~J}\)
2 \(75 \mathrm{~J}\)
3 \(100 \mathrm{~J}\)
4 \(25 \mathrm{~J}\)