A lift is going up. The total mass of the lift and the passenger is \(1500\) kg. The lift's speed varies as shown in the graph. The tension in the rope pulling the lift at \(t=11^{\text{th}}\) s will be:

      
1. \(17400\) N
2. \(14700\) N
3. \(12000\) N
4. Zero

Subtopic:  Application of Laws |
Level 3: 35%-60%
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A player caught a cricket ball of mass \(150\ \text{g}\) moving at a rate of \(20\ \text{m/s}\). If the catching process is completed in \(0.1\ \text{s}\), then the force of the blow exerted by the ball on the hands of the player is:

1. \(0.3\ \text{N}\)
2. \(30\ \text{N}\)
3. \(300\ \text{N}\)
4. \(3000\ \text{N}\)

Subtopic:  Newton's Laws |
 84%
Level 1: 80%+
PMT - 2001
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A rocket of mass \(100\ \text{kg}\) ejects exhaust gases at a rate of \(1\ \text{kg/s}\) with a velocity of \(500\ \text{m/s}\) relative to the rocket. Neglecting external forces, the initial thrust produced by the rocket is:

1. Zero
2. \(500\ \text{N}\)
3. \(1000\ \text{N}\)
4. \(2000\ \text{N}\)

Subtopic:  Variable Mass System |
 78%
Level 2: 60%+
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In which of the following cases, a force will not be required to keep the particle in the given motion?
(A) The particle is going in a circle.
(B) The particle is going along a straight line.
(C) The momentum of the particle is constant.
(D) The acceleration of the particle is constant.

Choose the correct option from given ones:
1. (A) and (B)
2. (A) and (D)
3. (B) and (C)
4. (C) and (D)

Subtopic:  Newton's Laws |
 59%
Level 3: 35%-60%
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A ball of mass \(150\ \text{g}\) starts moving with an acceleration of \(20\ \text{m/s}^2\) when hit by a force, which acts on it for \(0.1\ \text{s}\). The impulsive force is:

1. \(0.5\ \text{N-s}\)
2. \(0.1\ \text{N-s}\)
3. \(0.3\ \text{N-s}\)
4. \(1.2\ \text{N-s}\)

Subtopic:  Newton's Laws |
 90%
Level 1: 80%+
PMT - 2003
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A body of constant mass has constant linear momentum. Which of the following quantities must remain constant? 

1. force.

2. velocity.

3. acceleration.

4. All of these

Subtopic:  Newton's Laws |
 61%
Level 2: 60%+
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Rocket engines lift a rocket from the Earth's surface because hot gases with high velocity:

1. push against the Earth.

2. push against the air.

3. react against the rocket and push it up.

4. heat up the air, which lifts the rocket.

Subtopic:  Variable Mass System |
 56%
Level 3: 35%-60%
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A force of \(50\) dynes is applied to a body of mass \(5\ \text{g}\), which is at rest for an interval of \(3\) seconds; then the impulse is: 

1. \(0 .15 × 10^{-3}  \ \text{Ns}\)
2. \(0 .98 × 10^{-3}\ \text{N s}\)
3. \(1.5 × 10^{-3}\ \text{N s}\)
4. \(2.5 × 10^{-3}\ \text{N s}\)

Subtopic:  Newton's Laws |
 77%
Level 2: 60%+
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Three forces start acting simultaneously on a particle moving with velocity \(\vec v\). These forces are represented in magnitude and direction by the three sides of a triangle \(ABC\) (as shown). The particle will now move with velocity:

1. \(\vec v\) remaining unchanged
2. Less than \(\vec v\)
3. Greater than \(\vec v\)
4. \(\vec v\) in the direction of the largest force \(BC\)

Subtopic:  Application of Laws |
 76%
Level 2: 60%+
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Two blocks are connected by a string as shown in the diagram. The upper block is hung by another string. A force \(F\) applied on the upper string produces an acceleration of in the upward direction in both the blocks. If \(T\) and \(T’\) be the tensions in the two parts of the string, then:

1. \(T = 70.8\ \text{N}\ \text{and}\ T’ = 47.2\ \text{N}\)
2. \(T = 58.8\ \text{N}\ \text{and}\ T’ = 47.2\ \text{N}\)
3. \(T = 70.8\ \text{N}\ \text{and}\ T’ = 58.8\ \text{N}\)
4. \(T = 70.8\ \text{N}\ \text{and}\ T’ = 40.2\ \text{N}\)

Subtopic:  Application of Laws |
 68%
Level 2: 60%+
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