Three blocks of masses \(1~\text{kg},2~\text{kg},2~\text{kg}\) lie in a line on a smooth horizontal plane, connected by two horizontal metallic wires (of negligible mass) – \(I\) & \(II.\) A horizontal force of \(10~\text{ N}\) acts on the \(1~\text{kg}\) block, as shown.
                           
The cross-sectional area \((A),\) length \((L)\) and Young's moduli \((Y)\) of the wires are related by:    \(A_I=2A_{II}\\ L_I=2L_{II}\\ Y_I=2Y_{II}\)
The acceleration of the system is:
1. \(1~\text{m/s}^2\)
2. \(2~\text{m/s}^2\)
3. \(1.5~\text{m/s}^2\)
4. \(0.5~\text{m/s}^2\)
Subtopic:  Application of Laws |
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Two masses as shown are suspended from a massless pulley. What would be the acceleration of the system when masses are left free?

          

1. \(2g/3\)
2. \(g/3\)
3. \(g/9\)
4. \(g/7\)
(where \(g\) is the acceleration due to gravity.)

Subtopic:  Application of Laws |
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Level 1: 80%+
AIPMT - 2000
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A person of mass \(60\) kg is inside a lift of mass \(940\) kg and presses the button on the control panel. The lift starts moving upwards with an acceleration of \(1.0~\text{ms}^{-2}\). If \(g=10~\text{ms}^{-2}\), the tension in the supporting cable is:
1. \(9680~\text{N}\)
2. \(11000~\text{N}\)
3. \(1200~\text{N}\)
4. \(8600~\text{N}\)

Subtopic:  Application of Laws |
 93%
Level 1: 80%+
AIPMT - 2011
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If force \(F=500-100t,\) then the function of impulse with time will be:
1. \( 500 t-50 t^2 \)
2. \( 50 t-10 \)
3. \( 50-t^2 \)
4. \( 100 t^2\)
 

Subtopic:  Application of Laws |
 90%
Level 1: 80%+
AIPMT - 1998
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A person of mass \(60~\text{kg}\) is standing in an elevator. Column-I lists different motion conditions of the elevator and Column-II provides the corresponding normal force (i.e., the force exerted by the floor on the person). Match the entries in Column-I with the appropriate values in Column-II.
Column-I Column-II
(A) Elevator moving at constant speed (I) Force on the floor by the person \(=600\) N
(B) Elevator accelerating upward at \(3~\text{ms}^{-2}\) (II) Force on the floor by the person \(=780\) N
(C) Elevator accelerating downward at \(3~\text{ms}^{-2}\) (III) Force on the floor by the person \(=420\) N
 
1. \(\mathrm{A\text-I,B\text-II,C\text-III}\) 2. \(\mathrm{A\text-II,B\text-I,C\text-III}\)
3. \(\mathrm{A\text-III,B\text-I,C\text-II}\) 4. \(\mathrm{A\text-III,B\text-II,C\text-I}\)
Subtopic:  Application of Laws |
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A person standing on a spring balance inside a stationary lift measures \(60~\text{kg}\). The weight (in N) of that person if the lift descends with the uniform downward acceleration of \(1.8~\text{m/s}^2\) will be: [\(g=10~\text{m/s}^2\)]
1. \(600~\text{N}\)
2. \(500~\text{N}\)
3. \(492~\text{N}\)
4. \(450~\text{N}\)

Subtopic:  Application of Laws |
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A block of metal weighing 2 kg is resting on a frictionless plane (as shown in the figure). It is struck by a jet releasing water at a rate of 1 kgs-1 and at a speed of 10 ms-1. Then, the initial acceleration of the block, in ms-2, will be:

            

1. 3
2. 6
3. 5
4. 4
Subtopic:  Application of Laws |
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JEE
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A person of mass 60 kg is inside a lift of mass 940 kg and presses the button on control panel. The lift starts moving upwards with an acceleration 1.0 m/s2. If g=10 m/s2, the tension in the supporting cable is:

1. 9680 N

2. 11000 N

3. 1200 N

4. 8600 N

Subtopic:  Application of Laws |
 89%
Level 1: 80%+
NEET - 2011
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Pulley and strings shown in the figure are massless. Acceleration of 3 kg block is: [Take g = 10 m/s2]

                                     

(1) 1 m/s2

(2) 2 m/s2

(3) 3 m/s2

(4) 4 m/s2

Subtopic:  Application of Laws |
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The motion of a particle of mass \(m\) is described by \(y=ut+\frac{1}{2}gt^{2}.\)  The force acting on the particle is: 
1. \(3mg\)
2. \(mg\)
3. \(\frac{mg}{2}\)
4. \(2mg\)

Subtopic:  Application of Laws |
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Level 1: 80%+
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