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

149111 A bullet of mass $1 \mathrm{~kg}$ fired with speed $2 \mathrm{~ms}^{-1}$ from $x=0$ passes through a block of wood whose centre is kept at a distance of $10 \mathrm{~m}$ from the origin as shown in the figure. The retarding force $F_{r}$ on the bullet within the wooden block is $-0.5 / x$. The minimum length of the block (upto one decimal digit) required to completely stop the bullet is (Assume, $\mathrm{e}^{4}=\mathbf{5 5}$ )

1 $10.1 \mathrm{~m}$
2 $9.2 \mathrm{~m}$
3 $9.7 \mathrm{~m}$
4 $19.3 \mathrm{~m}$
Work, Energy and Power

149112 A light rigid wire of length $1 \mathrm{~m}$ is attached to a ball $A$ of mass $500 \mathrm{~g}$ to one end. The other end of the wire is fixed, so that the wire can rotate freely in the vertical plane about its fixed end. At the lowest point of the circular motion, the ball is given a horizontal velocity $6 \mathrm{~m} / \mathrm{s}$. Determined the radial component of the acceleration of the ball, when this rigid wire makes an angle $60^{\circ}$ with the upward vertical.
(Take, $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $10 \mathrm{~m} / \mathrm{s}^{2}$
2 $6 \mathrm{~m} / \mathrm{s}^{2}$
3 $18 \mathrm{~m} / \mathrm{s}^{2}$
4 $25 \mathrm{~m} / \mathrm{s}^{2}$
Work, Energy and Power

149113 A circular ring of mass $10 \mathrm{~kg}$ rolls along a horizontal floor. The center of mass of the ring has a speed $1.5 \mathrm{~m} / \mathrm{s}$. The work required to stop the ring is

1 $10 \mathrm{~J}$
2 $-6 \mathrm{~J}$
3 $14.5 \mathrm{~J}$
4 $-22.5 \mathrm{~J}$
Work, Energy and Power

149114 A bouncing ball of mass $200 \mathrm{~g}$ falls from the height of $5 \mathrm{~m}$ on a horizontal ground. After every impact with the ground, the velocity of the ball decreases by $\frac{1}{2}$ times.
The total momentum, the ball imparts on to the ground after 3 impacts is (let $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $\frac{14}{4} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
2 $\frac{20}{6} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
3 $\frac{26}{12} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
4 $\frac{21}{4} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
Work, Energy and Power

149115 A box of mass $3 \mathrm{~kg}$ moves on a horizontal frictionless table and collides with another box of mass $3 \mathrm{~kg}$ initially at rest on the edge of the table at height $1 \mathrm{~m}$. The speed of the moving box just before the collision is $4 \mathrm{~m} / \mathrm{s}$. The two boxes stick together and fall from the table. The kinetic energy just before the boxes strike the floor is (Assume, acceleration due to gravity, $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $40 \mathrm{~J}$
2 $80 \mathrm{~J}$
3 $96 \mathrm{~J}$
4 $72 \mathrm{~J}$
Work, Energy and Power

149111 A bullet of mass $1 \mathrm{~kg}$ fired with speed $2 \mathrm{~ms}^{-1}$ from $x=0$ passes through a block of wood whose centre is kept at a distance of $10 \mathrm{~m}$ from the origin as shown in the figure. The retarding force $F_{r}$ on the bullet within the wooden block is $-0.5 / x$. The minimum length of the block (upto one decimal digit) required to completely stop the bullet is (Assume, $\mathrm{e}^{4}=\mathbf{5 5}$ )

1 $10.1 \mathrm{~m}$
2 $9.2 \mathrm{~m}$
3 $9.7 \mathrm{~m}$
4 $19.3 \mathrm{~m}$
Work, Energy and Power

149112 A light rigid wire of length $1 \mathrm{~m}$ is attached to a ball $A$ of mass $500 \mathrm{~g}$ to one end. The other end of the wire is fixed, so that the wire can rotate freely in the vertical plane about its fixed end. At the lowest point of the circular motion, the ball is given a horizontal velocity $6 \mathrm{~m} / \mathrm{s}$. Determined the radial component of the acceleration of the ball, when this rigid wire makes an angle $60^{\circ}$ with the upward vertical.
(Take, $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $10 \mathrm{~m} / \mathrm{s}^{2}$
2 $6 \mathrm{~m} / \mathrm{s}^{2}$
3 $18 \mathrm{~m} / \mathrm{s}^{2}$
4 $25 \mathrm{~m} / \mathrm{s}^{2}$
Work, Energy and Power

149113 A circular ring of mass $10 \mathrm{~kg}$ rolls along a horizontal floor. The center of mass of the ring has a speed $1.5 \mathrm{~m} / \mathrm{s}$. The work required to stop the ring is

1 $10 \mathrm{~J}$
2 $-6 \mathrm{~J}$
3 $14.5 \mathrm{~J}$
4 $-22.5 \mathrm{~J}$
Work, Energy and Power

149114 A bouncing ball of mass $200 \mathrm{~g}$ falls from the height of $5 \mathrm{~m}$ on a horizontal ground. After every impact with the ground, the velocity of the ball decreases by $\frac{1}{2}$ times.
The total momentum, the ball imparts on to the ground after 3 impacts is (let $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $\frac{14}{4} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
2 $\frac{20}{6} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
3 $\frac{26}{12} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
4 $\frac{21}{4} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
Work, Energy and Power

149115 A box of mass $3 \mathrm{~kg}$ moves on a horizontal frictionless table and collides with another box of mass $3 \mathrm{~kg}$ initially at rest on the edge of the table at height $1 \mathrm{~m}$. The speed of the moving box just before the collision is $4 \mathrm{~m} / \mathrm{s}$. The two boxes stick together and fall from the table. The kinetic energy just before the boxes strike the floor is (Assume, acceleration due to gravity, $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $40 \mathrm{~J}$
2 $80 \mathrm{~J}$
3 $96 \mathrm{~J}$
4 $72 \mathrm{~J}$
NEET Test Series from KOTA - 10 Papers In MS WORD WhatsApp Here
Work, Energy and Power

149111 A bullet of mass $1 \mathrm{~kg}$ fired with speed $2 \mathrm{~ms}^{-1}$ from $x=0$ passes through a block of wood whose centre is kept at a distance of $10 \mathrm{~m}$ from the origin as shown in the figure. The retarding force $F_{r}$ on the bullet within the wooden block is $-0.5 / x$. The minimum length of the block (upto one decimal digit) required to completely stop the bullet is (Assume, $\mathrm{e}^{4}=\mathbf{5 5}$ )

1 $10.1 \mathrm{~m}$
2 $9.2 \mathrm{~m}$
3 $9.7 \mathrm{~m}$
4 $19.3 \mathrm{~m}$
Work, Energy and Power

149112 A light rigid wire of length $1 \mathrm{~m}$ is attached to a ball $A$ of mass $500 \mathrm{~g}$ to one end. The other end of the wire is fixed, so that the wire can rotate freely in the vertical plane about its fixed end. At the lowest point of the circular motion, the ball is given a horizontal velocity $6 \mathrm{~m} / \mathrm{s}$. Determined the radial component of the acceleration of the ball, when this rigid wire makes an angle $60^{\circ}$ with the upward vertical.
(Take, $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $10 \mathrm{~m} / \mathrm{s}^{2}$
2 $6 \mathrm{~m} / \mathrm{s}^{2}$
3 $18 \mathrm{~m} / \mathrm{s}^{2}$
4 $25 \mathrm{~m} / \mathrm{s}^{2}$
Work, Energy and Power

149113 A circular ring of mass $10 \mathrm{~kg}$ rolls along a horizontal floor. The center of mass of the ring has a speed $1.5 \mathrm{~m} / \mathrm{s}$. The work required to stop the ring is

1 $10 \mathrm{~J}$
2 $-6 \mathrm{~J}$
3 $14.5 \mathrm{~J}$
4 $-22.5 \mathrm{~J}$
Work, Energy and Power

149114 A bouncing ball of mass $200 \mathrm{~g}$ falls from the height of $5 \mathrm{~m}$ on a horizontal ground. After every impact with the ground, the velocity of the ball decreases by $\frac{1}{2}$ times.
The total momentum, the ball imparts on to the ground after 3 impacts is (let $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $\frac{14}{4} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
2 $\frac{20}{6} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
3 $\frac{26}{12} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
4 $\frac{21}{4} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
Work, Energy and Power

149115 A box of mass $3 \mathrm{~kg}$ moves on a horizontal frictionless table and collides with another box of mass $3 \mathrm{~kg}$ initially at rest on the edge of the table at height $1 \mathrm{~m}$. The speed of the moving box just before the collision is $4 \mathrm{~m} / \mathrm{s}$. The two boxes stick together and fall from the table. The kinetic energy just before the boxes strike the floor is (Assume, acceleration due to gravity, $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $40 \mathrm{~J}$
2 $80 \mathrm{~J}$
3 $96 \mathrm{~J}$
4 $72 \mathrm{~J}$
Work, Energy and Power

149111 A bullet of mass $1 \mathrm{~kg}$ fired with speed $2 \mathrm{~ms}^{-1}$ from $x=0$ passes through a block of wood whose centre is kept at a distance of $10 \mathrm{~m}$ from the origin as shown in the figure. The retarding force $F_{r}$ on the bullet within the wooden block is $-0.5 / x$. The minimum length of the block (upto one decimal digit) required to completely stop the bullet is (Assume, $\mathrm{e}^{4}=\mathbf{5 5}$ )

1 $10.1 \mathrm{~m}$
2 $9.2 \mathrm{~m}$
3 $9.7 \mathrm{~m}$
4 $19.3 \mathrm{~m}$
Work, Energy and Power

149112 A light rigid wire of length $1 \mathrm{~m}$ is attached to a ball $A$ of mass $500 \mathrm{~g}$ to one end. The other end of the wire is fixed, so that the wire can rotate freely in the vertical plane about its fixed end. At the lowest point of the circular motion, the ball is given a horizontal velocity $6 \mathrm{~m} / \mathrm{s}$. Determined the radial component of the acceleration of the ball, when this rigid wire makes an angle $60^{\circ}$ with the upward vertical.
(Take, $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $10 \mathrm{~m} / \mathrm{s}^{2}$
2 $6 \mathrm{~m} / \mathrm{s}^{2}$
3 $18 \mathrm{~m} / \mathrm{s}^{2}$
4 $25 \mathrm{~m} / \mathrm{s}^{2}$
Work, Energy and Power

149113 A circular ring of mass $10 \mathrm{~kg}$ rolls along a horizontal floor. The center of mass of the ring has a speed $1.5 \mathrm{~m} / \mathrm{s}$. The work required to stop the ring is

1 $10 \mathrm{~J}$
2 $-6 \mathrm{~J}$
3 $14.5 \mathrm{~J}$
4 $-22.5 \mathrm{~J}$
Work, Energy and Power

149114 A bouncing ball of mass $200 \mathrm{~g}$ falls from the height of $5 \mathrm{~m}$ on a horizontal ground. After every impact with the ground, the velocity of the ball decreases by $\frac{1}{2}$ times.
The total momentum, the ball imparts on to the ground after 3 impacts is (let $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $\frac{14}{4} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
2 $\frac{20}{6} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
3 $\frac{26}{12} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
4 $\frac{21}{4} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
Work, Energy and Power

149115 A box of mass $3 \mathrm{~kg}$ moves on a horizontal frictionless table and collides with another box of mass $3 \mathrm{~kg}$ initially at rest on the edge of the table at height $1 \mathrm{~m}$. The speed of the moving box just before the collision is $4 \mathrm{~m} / \mathrm{s}$. The two boxes stick together and fall from the table. The kinetic energy just before the boxes strike the floor is (Assume, acceleration due to gravity, $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $40 \mathrm{~J}$
2 $80 \mathrm{~J}$
3 $96 \mathrm{~J}$
4 $72 \mathrm{~J}$
Work, Energy and Power

149111 A bullet of mass $1 \mathrm{~kg}$ fired with speed $2 \mathrm{~ms}^{-1}$ from $x=0$ passes through a block of wood whose centre is kept at a distance of $10 \mathrm{~m}$ from the origin as shown in the figure. The retarding force $F_{r}$ on the bullet within the wooden block is $-0.5 / x$. The minimum length of the block (upto one decimal digit) required to completely stop the bullet is (Assume, $\mathrm{e}^{4}=\mathbf{5 5}$ )

1 $10.1 \mathrm{~m}$
2 $9.2 \mathrm{~m}$
3 $9.7 \mathrm{~m}$
4 $19.3 \mathrm{~m}$
Work, Energy and Power

149112 A light rigid wire of length $1 \mathrm{~m}$ is attached to a ball $A$ of mass $500 \mathrm{~g}$ to one end. The other end of the wire is fixed, so that the wire can rotate freely in the vertical plane about its fixed end. At the lowest point of the circular motion, the ball is given a horizontal velocity $6 \mathrm{~m} / \mathrm{s}$. Determined the radial component of the acceleration of the ball, when this rigid wire makes an angle $60^{\circ}$ with the upward vertical.
(Take, $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $10 \mathrm{~m} / \mathrm{s}^{2}$
2 $6 \mathrm{~m} / \mathrm{s}^{2}$
3 $18 \mathrm{~m} / \mathrm{s}^{2}$
4 $25 \mathrm{~m} / \mathrm{s}^{2}$
Work, Energy and Power

149113 A circular ring of mass $10 \mathrm{~kg}$ rolls along a horizontal floor. The center of mass of the ring has a speed $1.5 \mathrm{~m} / \mathrm{s}$. The work required to stop the ring is

1 $10 \mathrm{~J}$
2 $-6 \mathrm{~J}$
3 $14.5 \mathrm{~J}$
4 $-22.5 \mathrm{~J}$
Work, Energy and Power

149114 A bouncing ball of mass $200 \mathrm{~g}$ falls from the height of $5 \mathrm{~m}$ on a horizontal ground. After every impact with the ground, the velocity of the ball decreases by $\frac{1}{2}$ times.
The total momentum, the ball imparts on to the ground after 3 impacts is (let $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $\frac{14}{4} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
2 $\frac{20}{6} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
3 $\frac{26}{12} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
4 $\frac{21}{4} \mathrm{~kg} \mathrm{~m} / \mathrm{s}$
Work, Energy and Power

149115 A box of mass $3 \mathrm{~kg}$ moves on a horizontal frictionless table and collides with another box of mass $3 \mathrm{~kg}$ initially at rest on the edge of the table at height $1 \mathrm{~m}$. The speed of the moving box just before the collision is $4 \mathrm{~m} / \mathrm{s}$. The two boxes stick together and fall from the table. The kinetic energy just before the boxes strike the floor is (Assume, acceleration due to gravity, $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}$ )

1 $40 \mathrm{~J}$
2 $80 \mathrm{~J}$
3 $96 \mathrm{~J}$
4 $72 \mathrm{~J}$