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A \(200~\text g\) ball is thrown upward by applying constant upward force \((F)\) over a distance of \(50~\text{cm}\) and then releasing it;    the ball ascends to a height of \(10~\text m\) after it is released. The work done by the applied force \(F\) is: (take \(g=10~\text{m/s}^2\))
1. \(20~\text J\)
2. \(19~\text J\)
3. \(21~\text J\)
4. \(42~\text J\)

Subtopic:  Work done by constant force |
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Two blocks \(A\) & \(B\) of equal masses are connected by means of a light string passing over a smooth pulley: block \(A\) being held on a smooth horizontal plane, while \(B\) hangs vertically. The system is released from rest. The speed of the block \(B,\) after it falls through \(20~\text{cm},\) is: (Take \(g=10~\text{m/s}^2\))
1. \(1~\text{m/s}\) 2. \(2~\text{m/s}\)
3. \(\sqrt2~\text{m/s}\) 4. \({\Large\frac{1}{\sqrt2}}~\text{m/s}\)
Subtopic:  Conservation of Mechanical Energy |
 53%
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A car starts from rest along straight horizontal road under the action of an engine that delivers constant power, \(P.\) The velocity, \(v,\) as a function of time \(t\) varies as given by:
1. \(v\propto t\)     2. \(v\propto \sqrt t\)    
3. \(v\propto {\Large\frac{1}{\sqrt t}}\) 4. \(v\propto t^{3/2}\)
Subtopic:  Power |
 63%
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A block of mass \(1~\text{kg}\) is given an initial velocity of \(2~\text{m/s}\) towards a \(2~\text{kg}\) block, which is initially at rest. The coefficient of restitution \((e),\) between the blocks, during their collision is \({\Large\frac{1}{2}}.\)
                                    
The relative velocity between the blocks, after the collision, has the magnitude:
1. \(2~\text{m/s}\)
2. \(1~\text{m/s}\)
3. \({\Large\frac12}~\text{m/s}\)
4. \({\Large\frac14}~\text{m/s}\)
Subtopic:  Collisions |
 84%
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A block of mass \(1~\text{kg}\) is given an initial velocity of \(2~\text{m/s}\) towards a \(2~\text{kg}\) block, which is initially at rest. The coefficient of restitution \((e),\) between the blocks, during their collision is \({\Large\frac{1}{2}}.\)
                                    
The momentum of the system, as a result of the collision:
1. increases
2. decreases
3. remains constant
4. decreases suddenly and then increases
Subtopic:  Collisions |
 89%
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A block of mass \(1~\text{kg}\) is given an initial velocity of \(2~\text{m/s}\) towards a \(2~\text{kg}\) block, which is initially at rest. The coefficient of restitution \((e),\) between the blocks, during their collision is \({\Large\frac{1}{2}}.\)
                                    
The velocity of the first block, after the collision, is:
1. \({\Large\frac12}~\text{m/s}\) 2. \(1~\text{m/s}\)
3. \(2~\text{m/s}\) 4. \(0~\text{m/s}\)
Subtopic:  Collisions |
 83%
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Given below are two statements: 
Assertion (A): In a swinging simple pendulum, the power delivered by gravity is maximum when the pendulum is at the lowest point.
Reason (R): The speed of the pendulum bob is highest when it reaches the lowest point and the power is given by \((\vec F.\vec v).\)
 
1. Both (A) and (R) are True and (R) is the correct explanation of (A).
2. Both (A) and (R) are True but (R) is not the correct explanation of (A).
3. (A) is True but (R) is False.
4. (A) is False but (R) is True.
Subtopic:  Power |
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A box of mass \(m\) is placed in an elevator (lift), which is moving downward at constant velocity. Let the work done by the normal reaction \((N)\) of the "ground" on the box be \(W_N,\) and the work done by gravity on the box be \(W_g\) in the same time. Then, which statement is true in the ground frame as well as the elevator's frame?
                                         
1. \(W_N=0,W_g>0\)
2. \(W_N>0,W_g=0\)
3. \(W_N=W_g=0\)
4. \(W_N+W_g=0\)
Subtopic:  Work Energy Theorem |
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Two blocks of masses \(m,2m\) are held against two compressed springs and released on a smooth, horizontal surface. After losing contact with the springs, they collide and come to rest. The energies of the springs before the blocks are released are \(E_1\) and \(E_2,\) while the masses of the blocks are \(m\) and \(2m,\) as shown in the figure. Then,
                             
1. \(E_1=E_2\)
2. \(E_1=2E_2\)
3. \(2E_1=E_2\)
4. \(E_1=4E_2\)
Subtopic:  Elastic Potential Energy |
 66%
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An elastic ball, released from a height, loses \(50\%\) of its kinetic energy on impact with the ground, which is horizontal. The coefficient of restitution is:
1. \({\Large\frac12}\)
2. \({\Large\frac{1}{\sqrt2}}\)
3. \({\Large\frac14}\)
4. \(\sqrt2-1\)
Subtopic:  Collisions |
 81%
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