01. Angular Displacement, Velocity and Acceleration
NEET Test Series from KOTA - 10 Papers In MS WORD WhatsApp Here
Rotational Motion

149794 A solid body rotates with angular velocity \(\omega=a t \hat{\mathbf{i}}+b t^{2} \hat{\mathbf{j}}\) where \(a=1 \mathrm{rad} / \mathrm{s}^{2}\) and \(b=0.5\) \(\mathrm{rad} / \mathrm{s}^{2}\) and \(t\) is in seconds. Calculate the angle between the vectors of the angular velocity and the angular acceleration at \(\mathbf{t}=1\) sec.

1 \(\cos ^{-1}\left(\frac{5}{\sqrt{10}}\right)\)
2 \(\cos ^{-1}\left(\frac{4}{\sqrt{10}}\right)\)
3 \(\cos ^{-1}\left(\frac{2}{\sqrt{10}}\right)\)
4 \(\cos ^{-1}\left(\frac{3}{\sqrt{10}}\right)\)
Rotational Motion

149795 A disc has mass ' \(M\) ' and radius ' \(R\) '. How much tangential force should be applied to the rim of the disc so as to rotate with angular velocity ' \(\omega\) ' in time ' \(t\) '?

1 \(\frac{\mathrm{MR} \omega}{4 \mathrm{t}}\)
2 \(\frac{M R \omega}{2 t}\)
3 \(\frac{M R \omega}{t}\)
4 MRwt
Rotational Motion

149796 A uniform circular disc of mass ' \(M\) ' and radius ' \(R\) ' is rotating in a horizontal plane about an axis passing through its centre of mass and perpendicular to its plane with an angular velocity \(\omega\). Another disc of same radius but mass \((M / 2)\) is placed gently on the first disc. The angular velocity of the system now is

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

149797 The angular speed of the wheel of a vehicle is increased from \(360 \mathrm{rpm}\) to \(1200 \mathrm{rpm}\) in \(14 \mathrm{~s}\). Its angular acceleration is

1 \(2 \pi \mathrm{rad} / \mathrm{s}^{2}\)
2 \(28 \pi \mathrm{rad} / \mathrm{s}^{2}\)
3 \(120 \pi \mathrm{rad} / \mathrm{s}^{2}\)
4 \(1 \mathrm{rad} / \mathrm{s}^{2}\)
Rotational Motion

149794 A solid body rotates with angular velocity \(\omega=a t \hat{\mathbf{i}}+b t^{2} \hat{\mathbf{j}}\) where \(a=1 \mathrm{rad} / \mathrm{s}^{2}\) and \(b=0.5\) \(\mathrm{rad} / \mathrm{s}^{2}\) and \(t\) is in seconds. Calculate the angle between the vectors of the angular velocity and the angular acceleration at \(\mathbf{t}=1\) sec.

1 \(\cos ^{-1}\left(\frac{5}{\sqrt{10}}\right)\)
2 \(\cos ^{-1}\left(\frac{4}{\sqrt{10}}\right)\)
3 \(\cos ^{-1}\left(\frac{2}{\sqrt{10}}\right)\)
4 \(\cos ^{-1}\left(\frac{3}{\sqrt{10}}\right)\)
Rotational Motion

149795 A disc has mass ' \(M\) ' and radius ' \(R\) '. How much tangential force should be applied to the rim of the disc so as to rotate with angular velocity ' \(\omega\) ' in time ' \(t\) '?

1 \(\frac{\mathrm{MR} \omega}{4 \mathrm{t}}\)
2 \(\frac{M R \omega}{2 t}\)
3 \(\frac{M R \omega}{t}\)
4 MRwt
Rotational Motion

149796 A uniform circular disc of mass ' \(M\) ' and radius ' \(R\) ' is rotating in a horizontal plane about an axis passing through its centre of mass and perpendicular to its plane with an angular velocity \(\omega\). Another disc of same radius but mass \((M / 2)\) is placed gently on the first disc. The angular velocity of the system now is

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

149797 The angular speed of the wheel of a vehicle is increased from \(360 \mathrm{rpm}\) to \(1200 \mathrm{rpm}\) in \(14 \mathrm{~s}\). Its angular acceleration is

1 \(2 \pi \mathrm{rad} / \mathrm{s}^{2}\)
2 \(28 \pi \mathrm{rad} / \mathrm{s}^{2}\)
3 \(120 \pi \mathrm{rad} / \mathrm{s}^{2}\)
4 \(1 \mathrm{rad} / \mathrm{s}^{2}\)
Rotational Motion

149794 A solid body rotates with angular velocity \(\omega=a t \hat{\mathbf{i}}+b t^{2} \hat{\mathbf{j}}\) where \(a=1 \mathrm{rad} / \mathrm{s}^{2}\) and \(b=0.5\) \(\mathrm{rad} / \mathrm{s}^{2}\) and \(t\) is in seconds. Calculate the angle between the vectors of the angular velocity and the angular acceleration at \(\mathbf{t}=1\) sec.

1 \(\cos ^{-1}\left(\frac{5}{\sqrt{10}}\right)\)
2 \(\cos ^{-1}\left(\frac{4}{\sqrt{10}}\right)\)
3 \(\cos ^{-1}\left(\frac{2}{\sqrt{10}}\right)\)
4 \(\cos ^{-1}\left(\frac{3}{\sqrt{10}}\right)\)
Rotational Motion

149795 A disc has mass ' \(M\) ' and radius ' \(R\) '. How much tangential force should be applied to the rim of the disc so as to rotate with angular velocity ' \(\omega\) ' in time ' \(t\) '?

1 \(\frac{\mathrm{MR} \omega}{4 \mathrm{t}}\)
2 \(\frac{M R \omega}{2 t}\)
3 \(\frac{M R \omega}{t}\)
4 MRwt
Rotational Motion

149796 A uniform circular disc of mass ' \(M\) ' and radius ' \(R\) ' is rotating in a horizontal plane about an axis passing through its centre of mass and perpendicular to its plane with an angular velocity \(\omega\). Another disc of same radius but mass \((M / 2)\) is placed gently on the first disc. The angular velocity of the system now is

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

149797 The angular speed of the wheel of a vehicle is increased from \(360 \mathrm{rpm}\) to \(1200 \mathrm{rpm}\) in \(14 \mathrm{~s}\). Its angular acceleration is

1 \(2 \pi \mathrm{rad} / \mathrm{s}^{2}\)
2 \(28 \pi \mathrm{rad} / \mathrm{s}^{2}\)
3 \(120 \pi \mathrm{rad} / \mathrm{s}^{2}\)
4 \(1 \mathrm{rad} / \mathrm{s}^{2}\)
NEET Test Series from KOTA - 10 Papers In MS WORD WhatsApp Here
Rotational Motion

149794 A solid body rotates with angular velocity \(\omega=a t \hat{\mathbf{i}}+b t^{2} \hat{\mathbf{j}}\) where \(a=1 \mathrm{rad} / \mathrm{s}^{2}\) and \(b=0.5\) \(\mathrm{rad} / \mathrm{s}^{2}\) and \(t\) is in seconds. Calculate the angle between the vectors of the angular velocity and the angular acceleration at \(\mathbf{t}=1\) sec.

1 \(\cos ^{-1}\left(\frac{5}{\sqrt{10}}\right)\)
2 \(\cos ^{-1}\left(\frac{4}{\sqrt{10}}\right)\)
3 \(\cos ^{-1}\left(\frac{2}{\sqrt{10}}\right)\)
4 \(\cos ^{-1}\left(\frac{3}{\sqrt{10}}\right)\)
Rotational Motion

149795 A disc has mass ' \(M\) ' and radius ' \(R\) '. How much tangential force should be applied to the rim of the disc so as to rotate with angular velocity ' \(\omega\) ' in time ' \(t\) '?

1 \(\frac{\mathrm{MR} \omega}{4 \mathrm{t}}\)
2 \(\frac{M R \omega}{2 t}\)
3 \(\frac{M R \omega}{t}\)
4 MRwt
Rotational Motion

149796 A uniform circular disc of mass ' \(M\) ' and radius ' \(R\) ' is rotating in a horizontal plane about an axis passing through its centre of mass and perpendicular to its plane with an angular velocity \(\omega\). Another disc of same radius but mass \((M / 2)\) is placed gently on the first disc. The angular velocity of the system now is

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

149797 The angular speed of the wheel of a vehicle is increased from \(360 \mathrm{rpm}\) to \(1200 \mathrm{rpm}\) in \(14 \mathrm{~s}\). Its angular acceleration is

1 \(2 \pi \mathrm{rad} / \mathrm{s}^{2}\)
2 \(28 \pi \mathrm{rad} / \mathrm{s}^{2}\)
3 \(120 \pi \mathrm{rad} / \mathrm{s}^{2}\)
4 \(1 \mathrm{rad} / \mathrm{s}^{2}\)