02. Conservation of Energy and Work Energy Theorem
Work, Energy and Power

149144 An $80 \mathrm{~kg}$ man is riding on a small $40 \mathrm{~kg}$ cart at a speed of $4 \mathrm{~m} / \mathrm{s}$. He jumps off the cart with zero horizontal speed. What is the resulting changes in the speed of the cart (in $\mathrm{m} / \mathrm{s}$ )?

1 4
2 8
3 12
4 0
Work, Energy and Power

149145 Two bodies with kinetic energies in the ratio 4:1 are moving with equal linear momentum. The ratio of their masses is

1 $1: 2$
2 $1: 1$
3 $4: 1$
4 $1: 4$
Work, Energy and Power

149146 A body of mass $1 \mathrm{~kg}$ is thrown upwards with a velocity $20 \mathrm{~ms}^{-1}$. It momentarily comes to rest after attaining a height of $18 \mathrm{~m}$. How much energy is lost due to air friction? (Take $g=$ $10 \mathrm{~ms}^{-2}$ )

1 $20 \mathrm{~J}$
2 $30 \mathrm{~J}$
3 $40 \mathrm{~J}$
4 $10 \mathrm{~J}$
Work, Energy and Power

149147 When a body is thrown vertically upwards with a velocity of $50 \mathrm{~m} / \mathrm{s}$, the percentage of its initial kinetic energy converted into potential energy after 4 seconds is:
( $\mathrm{g}=\mathbf{1 0} \mathrm{ms}^{-\mathbf{2}}$ )

1 $96 \%$
2 $50 \%$
3 $24 \%$
4 $4 \%$
Work, Energy and Power

149148 A steel ball of mass $0.1 \mathrm{~kg}$ falls freely from a height of $10 \mathrm{~m}$ and bounces to a height of $5.4 \mathrm{~m}$ from the ground. If the dissipated energy in this process is absorbed by the ball, the rise in its temperature is:
(The specific heat of steel is $460 \mathrm{~J} / \mathrm{kg}^{\circ} \mathrm{C}$ )

1 $0.01^{\circ} \mathrm{C}$
2 $0.1^{\circ} \mathrm{C}$
3 $1{ }^{\circ} \mathrm{C}$
4 $1.1^{\circ} \mathrm{C}$
Work, Energy and Power

149144 An $80 \mathrm{~kg}$ man is riding on a small $40 \mathrm{~kg}$ cart at a speed of $4 \mathrm{~m} / \mathrm{s}$. He jumps off the cart with zero horizontal speed. What is the resulting changes in the speed of the cart (in $\mathrm{m} / \mathrm{s}$ )?

1 4
2 8
3 12
4 0
Work, Energy and Power

149145 Two bodies with kinetic energies in the ratio 4:1 are moving with equal linear momentum. The ratio of their masses is

1 $1: 2$
2 $1: 1$
3 $4: 1$
4 $1: 4$
Work, Energy and Power

149146 A body of mass $1 \mathrm{~kg}$ is thrown upwards with a velocity $20 \mathrm{~ms}^{-1}$. It momentarily comes to rest after attaining a height of $18 \mathrm{~m}$. How much energy is lost due to air friction? (Take $g=$ $10 \mathrm{~ms}^{-2}$ )

1 $20 \mathrm{~J}$
2 $30 \mathrm{~J}$
3 $40 \mathrm{~J}$
4 $10 \mathrm{~J}$
Work, Energy and Power

149147 When a body is thrown vertically upwards with a velocity of $50 \mathrm{~m} / \mathrm{s}$, the percentage of its initial kinetic energy converted into potential energy after 4 seconds is:
( $\mathrm{g}=\mathbf{1 0} \mathrm{ms}^{-\mathbf{2}}$ )

1 $96 \%$
2 $50 \%$
3 $24 \%$
4 $4 \%$
Work, Energy and Power

149148 A steel ball of mass $0.1 \mathrm{~kg}$ falls freely from a height of $10 \mathrm{~m}$ and bounces to a height of $5.4 \mathrm{~m}$ from the ground. If the dissipated energy in this process is absorbed by the ball, the rise in its temperature is:
(The specific heat of steel is $460 \mathrm{~J} / \mathrm{kg}^{\circ} \mathrm{C}$ )

1 $0.01^{\circ} \mathrm{C}$
2 $0.1^{\circ} \mathrm{C}$
3 $1{ }^{\circ} \mathrm{C}$
4 $1.1^{\circ} \mathrm{C}$
Work, Energy and Power

149144 An $80 \mathrm{~kg}$ man is riding on a small $40 \mathrm{~kg}$ cart at a speed of $4 \mathrm{~m} / \mathrm{s}$. He jumps off the cart with zero horizontal speed. What is the resulting changes in the speed of the cart (in $\mathrm{m} / \mathrm{s}$ )?

1 4
2 8
3 12
4 0
Work, Energy and Power

149145 Two bodies with kinetic energies in the ratio 4:1 are moving with equal linear momentum. The ratio of their masses is

1 $1: 2$
2 $1: 1$
3 $4: 1$
4 $1: 4$
Work, Energy and Power

149146 A body of mass $1 \mathrm{~kg}$ is thrown upwards with a velocity $20 \mathrm{~ms}^{-1}$. It momentarily comes to rest after attaining a height of $18 \mathrm{~m}$. How much energy is lost due to air friction? (Take $g=$ $10 \mathrm{~ms}^{-2}$ )

1 $20 \mathrm{~J}$
2 $30 \mathrm{~J}$
3 $40 \mathrm{~J}$
4 $10 \mathrm{~J}$
Work, Energy and Power

149147 When a body is thrown vertically upwards with a velocity of $50 \mathrm{~m} / \mathrm{s}$, the percentage of its initial kinetic energy converted into potential energy after 4 seconds is:
( $\mathrm{g}=\mathbf{1 0} \mathrm{ms}^{-\mathbf{2}}$ )

1 $96 \%$
2 $50 \%$
3 $24 \%$
4 $4 \%$
Work, Energy and Power

149148 A steel ball of mass $0.1 \mathrm{~kg}$ falls freely from a height of $10 \mathrm{~m}$ and bounces to a height of $5.4 \mathrm{~m}$ from the ground. If the dissipated energy in this process is absorbed by the ball, the rise in its temperature is:
(The specific heat of steel is $460 \mathrm{~J} / \mathrm{kg}^{\circ} \mathrm{C}$ )

1 $0.01^{\circ} \mathrm{C}$
2 $0.1^{\circ} \mathrm{C}$
3 $1{ }^{\circ} \mathrm{C}$
4 $1.1^{\circ} \mathrm{C}$
Work, Energy and Power

149144 An $80 \mathrm{~kg}$ man is riding on a small $40 \mathrm{~kg}$ cart at a speed of $4 \mathrm{~m} / \mathrm{s}$. He jumps off the cart with zero horizontal speed. What is the resulting changes in the speed of the cart (in $\mathrm{m} / \mathrm{s}$ )?

1 4
2 8
3 12
4 0
Work, Energy and Power

149145 Two bodies with kinetic energies in the ratio 4:1 are moving with equal linear momentum. The ratio of their masses is

1 $1: 2$
2 $1: 1$
3 $4: 1$
4 $1: 4$
Work, Energy and Power

149146 A body of mass $1 \mathrm{~kg}$ is thrown upwards with a velocity $20 \mathrm{~ms}^{-1}$. It momentarily comes to rest after attaining a height of $18 \mathrm{~m}$. How much energy is lost due to air friction? (Take $g=$ $10 \mathrm{~ms}^{-2}$ )

1 $20 \mathrm{~J}$
2 $30 \mathrm{~J}$
3 $40 \mathrm{~J}$
4 $10 \mathrm{~J}$
Work, Energy and Power

149147 When a body is thrown vertically upwards with a velocity of $50 \mathrm{~m} / \mathrm{s}$, the percentage of its initial kinetic energy converted into potential energy after 4 seconds is:
( $\mathrm{g}=\mathbf{1 0} \mathrm{ms}^{-\mathbf{2}}$ )

1 $96 \%$
2 $50 \%$
3 $24 \%$
4 $4 \%$
Work, Energy and Power

149148 A steel ball of mass $0.1 \mathrm{~kg}$ falls freely from a height of $10 \mathrm{~m}$ and bounces to a height of $5.4 \mathrm{~m}$ from the ground. If the dissipated energy in this process is absorbed by the ball, the rise in its temperature is:
(The specific heat of steel is $460 \mathrm{~J} / \mathrm{kg}^{\circ} \mathrm{C}$ )

1 $0.01^{\circ} \mathrm{C}$
2 $0.1^{\circ} \mathrm{C}$
3 $1{ }^{\circ} \mathrm{C}$
4 $1.1^{\circ} \mathrm{C}$
Work, Energy and Power

149144 An $80 \mathrm{~kg}$ man is riding on a small $40 \mathrm{~kg}$ cart at a speed of $4 \mathrm{~m} / \mathrm{s}$. He jumps off the cart with zero horizontal speed. What is the resulting changes in the speed of the cart (in $\mathrm{m} / \mathrm{s}$ )?

1 4
2 8
3 12
4 0
Work, Energy and Power

149145 Two bodies with kinetic energies in the ratio 4:1 are moving with equal linear momentum. The ratio of their masses is

1 $1: 2$
2 $1: 1$
3 $4: 1$
4 $1: 4$
Work, Energy and Power

149146 A body of mass $1 \mathrm{~kg}$ is thrown upwards with a velocity $20 \mathrm{~ms}^{-1}$. It momentarily comes to rest after attaining a height of $18 \mathrm{~m}$. How much energy is lost due to air friction? (Take $g=$ $10 \mathrm{~ms}^{-2}$ )

1 $20 \mathrm{~J}$
2 $30 \mathrm{~J}$
3 $40 \mathrm{~J}$
4 $10 \mathrm{~J}$
Work, Energy and Power

149147 When a body is thrown vertically upwards with a velocity of $50 \mathrm{~m} / \mathrm{s}$, the percentage of its initial kinetic energy converted into potential energy after 4 seconds is:
( $\mathrm{g}=\mathbf{1 0} \mathrm{ms}^{-\mathbf{2}}$ )

1 $96 \%$
2 $50 \%$
3 $24 \%$
4 $4 \%$
Work, Energy and Power

149148 A steel ball of mass $0.1 \mathrm{~kg}$ falls freely from a height of $10 \mathrm{~m}$ and bounces to a height of $5.4 \mathrm{~m}$ from the ground. If the dissipated energy in this process is absorbed by the ball, the rise in its temperature is:
(The specific heat of steel is $460 \mathrm{~J} / \mathrm{kg}^{\circ} \mathrm{C}$ )

1 $0.01^{\circ} \mathrm{C}$
2 $0.1^{\circ} \mathrm{C}$
3 $1{ }^{\circ} \mathrm{C}$
4 $1.1^{\circ} \mathrm{C}$