COLLISIONS
Work, Energy and Power

268908 At high altitude a body at rest explodes into two fragments of equal masses with one fragment receiving horizontal velocity of \(10 \mathrm{~ms}^{-1}\). Time taken by the two radius vectors connecting point of explosion to fragment to make \(90^{\circ}\) is \(\left(\mathrm{g}=10 \mathrm{~ms}^{-2}\right)\)

1 \(10 \mathrm{~s}\)
2 \(4 \mathrm{~s}\)
3 \(2 \mathrm{~s}\)
4 \(1 \mathrm{~s}\)
Work, Energy and Power

268905 A block of wood of mass \(3 \mathrm{M}\) is suspended by a string of length \(\frac{10}{3} \mathbf{m}\). A bullet of mass \(M\) hits it with a certain velocity and gets embedded in it. The block and the bullet swing to one side till the string makes \(120^{\circ}\) with the initial position. The velocity of the bullet is \(\left(\mathrm{g}=10 \mathrm{~ms}^{-2}\right)\)

1 \(\frac{40}{\sqrt{3}} \mathrm{~ms}^{-1}\)
2 \(20 \mathrm{~ms}^{-1}\)
3 \(30 \mathrm{~ms}^{-1}\)
4 \(40 \mathrm{~ms}^{-1}\)
Work, Energy and Power

268906 A wooden block of mass \(10 \mathrm{gm}\) is dropped from the top of a cliff \(100 \mathrm{~m}\) high. Simultaneously a bullet of same mass is fired from the foot of the cliff vertically upwards with a velocity of \(100 \mathrm{~ms}^{-1}\). If the bullet after collision gets embedded in the block, the common velocity of the bullet and the block immediately after collision is \(\left(\mathrm{g}=\mathbf{1 0} \mathrm{ms}^{-2}\right)\)

1 \(40 \mathrm{~ms}^{-1}\) downward
2 \(40 \mathrm{~ms}^{-1}\) upward
3 \(80 \mathrm{~ms}^{-1}\) upward
4 zero
Work, Energy and Power

268907 A particle of mass \(m\) has a velocity \(-v_{0} i\), while a second particle of same mass has a velocity \(\mathbf{v}_{\mathbf{0}} \mathbf{j}\). After the particles collide, first particle is found to have a velocity \(\frac{-1}{2} v_{0} \bar{i}\) then the velocity of other particle is

1 \(\frac{-1}{2} v_{0} \vec{i}+v_{0} \vec{j}\)
2 \(\frac{1}{2} v_{0} \vec{i}+v_{0} \vec{j}\)
3 \(v_{0} \vec{i}+v_{0} \vec{j}\)
4 \(-v_{0} \vec{i}+v_{0} \vec{j}\)
Work, Energy and Power

268908 At high altitude a body at rest explodes into two fragments of equal masses with one fragment receiving horizontal velocity of \(10 \mathrm{~ms}^{-1}\). Time taken by the two radius vectors connecting point of explosion to fragment to make \(90^{\circ}\) is \(\left(\mathrm{g}=10 \mathrm{~ms}^{-2}\right)\)

1 \(10 \mathrm{~s}\)
2 \(4 \mathrm{~s}\)
3 \(2 \mathrm{~s}\)
4 \(1 \mathrm{~s}\)
Work, Energy and Power

268905 A block of wood of mass \(3 \mathrm{M}\) is suspended by a string of length \(\frac{10}{3} \mathbf{m}\). A bullet of mass \(M\) hits it with a certain velocity and gets embedded in it. The block and the bullet swing to one side till the string makes \(120^{\circ}\) with the initial position. The velocity of the bullet is \(\left(\mathrm{g}=10 \mathrm{~ms}^{-2}\right)\)

1 \(\frac{40}{\sqrt{3}} \mathrm{~ms}^{-1}\)
2 \(20 \mathrm{~ms}^{-1}\)
3 \(30 \mathrm{~ms}^{-1}\)
4 \(40 \mathrm{~ms}^{-1}\)
Work, Energy and Power

268906 A wooden block of mass \(10 \mathrm{gm}\) is dropped from the top of a cliff \(100 \mathrm{~m}\) high. Simultaneously a bullet of same mass is fired from the foot of the cliff vertically upwards with a velocity of \(100 \mathrm{~ms}^{-1}\). If the bullet after collision gets embedded in the block, the common velocity of the bullet and the block immediately after collision is \(\left(\mathrm{g}=\mathbf{1 0} \mathrm{ms}^{-2}\right)\)

1 \(40 \mathrm{~ms}^{-1}\) downward
2 \(40 \mathrm{~ms}^{-1}\) upward
3 \(80 \mathrm{~ms}^{-1}\) upward
4 zero
Work, Energy and Power

268907 A particle of mass \(m\) has a velocity \(-v_{0} i\), while a second particle of same mass has a velocity \(\mathbf{v}_{\mathbf{0}} \mathbf{j}\). After the particles collide, first particle is found to have a velocity \(\frac{-1}{2} v_{0} \bar{i}\) then the velocity of other particle is

1 \(\frac{-1}{2} v_{0} \vec{i}+v_{0} \vec{j}\)
2 \(\frac{1}{2} v_{0} \vec{i}+v_{0} \vec{j}\)
3 \(v_{0} \vec{i}+v_{0} \vec{j}\)
4 \(-v_{0} \vec{i}+v_{0} \vec{j}\)
Work, Energy and Power

268908 At high altitude a body at rest explodes into two fragments of equal masses with one fragment receiving horizontal velocity of \(10 \mathrm{~ms}^{-1}\). Time taken by the two radius vectors connecting point of explosion to fragment to make \(90^{\circ}\) is \(\left(\mathrm{g}=10 \mathrm{~ms}^{-2}\right)\)

1 \(10 \mathrm{~s}\)
2 \(4 \mathrm{~s}\)
3 \(2 \mathrm{~s}\)
4 \(1 \mathrm{~s}\)
Work, Energy and Power

268905 A block of wood of mass \(3 \mathrm{M}\) is suspended by a string of length \(\frac{10}{3} \mathbf{m}\). A bullet of mass \(M\) hits it with a certain velocity and gets embedded in it. The block and the bullet swing to one side till the string makes \(120^{\circ}\) with the initial position. The velocity of the bullet is \(\left(\mathrm{g}=10 \mathrm{~ms}^{-2}\right)\)

1 \(\frac{40}{\sqrt{3}} \mathrm{~ms}^{-1}\)
2 \(20 \mathrm{~ms}^{-1}\)
3 \(30 \mathrm{~ms}^{-1}\)
4 \(40 \mathrm{~ms}^{-1}\)
Work, Energy and Power

268906 A wooden block of mass \(10 \mathrm{gm}\) is dropped from the top of a cliff \(100 \mathrm{~m}\) high. Simultaneously a bullet of same mass is fired from the foot of the cliff vertically upwards with a velocity of \(100 \mathrm{~ms}^{-1}\). If the bullet after collision gets embedded in the block, the common velocity of the bullet and the block immediately after collision is \(\left(\mathrm{g}=\mathbf{1 0} \mathrm{ms}^{-2}\right)\)

1 \(40 \mathrm{~ms}^{-1}\) downward
2 \(40 \mathrm{~ms}^{-1}\) upward
3 \(80 \mathrm{~ms}^{-1}\) upward
4 zero
Work, Energy and Power

268907 A particle of mass \(m\) has a velocity \(-v_{0} i\), while a second particle of same mass has a velocity \(\mathbf{v}_{\mathbf{0}} \mathbf{j}\). After the particles collide, first particle is found to have a velocity \(\frac{-1}{2} v_{0} \bar{i}\) then the velocity of other particle is

1 \(\frac{-1}{2} v_{0} \vec{i}+v_{0} \vec{j}\)
2 \(\frac{1}{2} v_{0} \vec{i}+v_{0} \vec{j}\)
3 \(v_{0} \vec{i}+v_{0} \vec{j}\)
4 \(-v_{0} \vec{i}+v_{0} \vec{j}\)
Work, Energy and Power

268908 At high altitude a body at rest explodes into two fragments of equal masses with one fragment receiving horizontal velocity of \(10 \mathrm{~ms}^{-1}\). Time taken by the two radius vectors connecting point of explosion to fragment to make \(90^{\circ}\) is \(\left(\mathrm{g}=10 \mathrm{~ms}^{-2}\right)\)

1 \(10 \mathrm{~s}\)
2 \(4 \mathrm{~s}\)
3 \(2 \mathrm{~s}\)
4 \(1 \mathrm{~s}\)
Work, Energy and Power

268905 A block of wood of mass \(3 \mathrm{M}\) is suspended by a string of length \(\frac{10}{3} \mathbf{m}\). A bullet of mass \(M\) hits it with a certain velocity and gets embedded in it. The block and the bullet swing to one side till the string makes \(120^{\circ}\) with the initial position. The velocity of the bullet is \(\left(\mathrm{g}=10 \mathrm{~ms}^{-2}\right)\)

1 \(\frac{40}{\sqrt{3}} \mathrm{~ms}^{-1}\)
2 \(20 \mathrm{~ms}^{-1}\)
3 \(30 \mathrm{~ms}^{-1}\)
4 \(40 \mathrm{~ms}^{-1}\)
Work, Energy and Power

268906 A wooden block of mass \(10 \mathrm{gm}\) is dropped from the top of a cliff \(100 \mathrm{~m}\) high. Simultaneously a bullet of same mass is fired from the foot of the cliff vertically upwards with a velocity of \(100 \mathrm{~ms}^{-1}\). If the bullet after collision gets embedded in the block, the common velocity of the bullet and the block immediately after collision is \(\left(\mathrm{g}=\mathbf{1 0} \mathrm{ms}^{-2}\right)\)

1 \(40 \mathrm{~ms}^{-1}\) downward
2 \(40 \mathrm{~ms}^{-1}\) upward
3 \(80 \mathrm{~ms}^{-1}\) upward
4 zero
Work, Energy and Power

268907 A particle of mass \(m\) has a velocity \(-v_{0} i\), while a second particle of same mass has a velocity \(\mathbf{v}_{\mathbf{0}} \mathbf{j}\). After the particles collide, first particle is found to have a velocity \(\frac{-1}{2} v_{0} \bar{i}\) then the velocity of other particle is

1 \(\frac{-1}{2} v_{0} \vec{i}+v_{0} \vec{j}\)
2 \(\frac{1}{2} v_{0} \vec{i}+v_{0} \vec{j}\)
3 \(v_{0} \vec{i}+v_{0} \vec{j}\)
4 \(-v_{0} \vec{i}+v_{0} \vec{j}\)