A car starts from rest and moves with uniform acceleration \(a\) on a straight road from time \(t = 0\) to \(t = T\). After that, a constant deceleration brings it to rest. In this process, the average speed of the car is: 

1. \(\dfrac{aT}{4}\)

2. \(\dfrac{3aT}{2}\)

3. \(\dfrac{aT}{2}\)

4. \(aT\)

Subtopic:  Uniformly Accelerated Motion |
 60%
Level 2: 60%+
PMT - 2004
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An object accelerates from rest to a velocity of \(27.5\ \text{m/s}\) in \(10\ \text{s}\). Then find the distance covered by the object in the next \(10\ \text{s}\):

1. \(550\ \text{m}\)
2. \(137.5\ \text{m}\)
3. \(412.5\ \text{m}\)
4. \(275\ \text{m}\)

Subtopic:  Uniformly Accelerated Motion |
 60%
Level 2: 60%+
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If the velocity of a particle is given by \(v = (180-16x)^{1/2}~\text{m/s} \), then its acceleration will be: 
1. zero
2. \(8\text{ m/s}^2\)
3. \(-8\text{ m/s}^2\)
4. \(4\text{ m/s}^2\)

Subtopic:  Acceleration |
 69%
Level 2: 60%+
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The displacement of a particle is proportional to the cube of the time elapsed. How does the acceleration of the particle depends on time obtained?

1. \(𝑎 ∝ t^ 2 \)
2. \(𝑎 ∝ 𝑡^ 4 \)
3. \(𝑎 ∝ 𝑡 ^3\)
4. \(𝑎 ∝ 𝑡  \)

Subtopic:  Acceleration |
 80%
Level 1: 80%+
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Starting from rest, the acceleration of a particle is \(𝑎 = 2 ( 𝑡 − 1 )\). The velocity of the particle at \(𝑡 = 5\ \text{𝑠}\) is:

1.  \(15\ \text{m/s}\)
2.  \(25\ \text{m/s}\)
3.  \(5\ \text{m/s}\)
4.  None of these

Subtopic:  Instantaneous Speed & Instantaneous Velocity |
 77%
Level 2: 60%+
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The speeds of two identical cars are \(u\) and \(4u\) at a specific instant. The ratio of the respective distances in which the two cars are stopped from that instant is:

1. \(1 : 1\)
2. \(1 : 4\)
3. \(1 : 8\)
4. \(1 : 16\)

Subtopic:  Acceleration |
 78%
Level 2: 60%+
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A body is moving with uniform acceleration describes \(40\ \text{m}\) in the first \(5\) seconds and \(65\ \text{m}\) in the next \(5\) seconds. Its initial velocity will be:

1. \(4\ \text{m/s}\)

2. \(2.5\ \text{m/s}\)

3. \(5.5\ \text{m/s}\)

4. \(11\ \text{m/s}\)

Subtopic:  Uniformly Accelerated Motion |
 69%
Level 2: 60%+
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The displacement \(x\) of a particle varies with time \(𝑡\), where \(𝑎,\ 𝑏,\ 𝛼\) and \(\beta\) are positive constants. The velocity of the particle will:

1. Go on decreasing with time
2. Be independent of \(𝛼\) and \(\beta\)
3. Drop to zero when \(𝛼 = 𝛽\)
4. Go on increasing with time

Subtopic:  Instantaneous Speed & Instantaneous Velocity |
 55%
Level 3: 35%-60%
PMT - 2005
Hints

A car, starting from rest, accelerates at the rate \(f\) through a distance \(S\), then continues at a constant speed for time \(t\) and then decelerates at the rate \(\frac f2\) to come to rest. If the total distance traversed is \(15\ \text{S}\), then:

1. \(S = \frac{1}{2}ft^2\)
2. \(S = \frac{1}{4}ft^2\)
3. \(S = \frac{1}{72}ft^2\)
4. \(S = \frac{1}{6}ft^2\)

Subtopic:  Acceleration |
 55%
Level 3: 35%-60%
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A man is \(45\ \text{m}\) behind the bus when the bus starts accelerating from rest with an acceleration of \(2.5\ \text{m/s}^2\). With what minimum velocity should the man start running to catch the bus?

1.  \(12\ \text{m/s}\)
2.  \(14\ \text{m/s}\)
3.  \(15\ \text{m/s}\)
4.  \(16\ \text{m/s}\)

Subtopic:  Relative Motion in One Dimension |
 81%
Level 1: 80%+
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