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. \(1 : 16\)
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. \(11\ \text{m/s}\)
The displacement \(x\) of a particle varies with time \(𝑡\) as \(x=ae^{\alpha t}+be^{\beta t}\) 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
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. \(S = \frac{1}{6}ft^2\)
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. \(16\ \text{m/s}\)
A particle moves along the x-axis as \({x}=4({t}-2)+{a}({t}-2)^2.\)Which of the following is true?
| 1. | The initial velocity of the particle is \(4\) |
| 2. | The acceleration of the particle is \(2a\) |
| 3. | The particle is at the origin at \( t = 0\) |
| 4. | None of these |
A body starting from rest moves with constant acceleration. The ratio of the distance covered by the body during the \(5^{th}\) second to that covered in \(5\) second is:
1. \(9/25\)
2. \(3/5\)
3. \(25/9\)
4. \(1/25\)
Two trains, each \(50\) m long, are travelling in the opposite direction with velocities \(10\) m/s and \(15\) m/s. The time of crossing is:
1. \(10\) sec
2. \(4\) sec
3. \(2\sqrt{3}\) sec
4. \(4\sqrt{3}\) sec
A \(120\ \text{m}\) long train is moving in a direction with speed \(20\ \text{m/s}\). A train \(B\), moving with \(30\ \text{m/s}\) in the opposite direction and \(130\ \text{m}\) long, crosses the first train in a time:
1. \(4\ \text{s}\)
2. \(36\ \text{s}\)
3. \(38\ \text{s}\)
4. \(5\ \text{s}\)
A \(210\) meter long train is moving due north at a speed of \(25\ \text{m/s}\). A small bird is flying due South a little above the train with a speed of \(5\ \text{m/s}\). The time taken by the bird to cross the train is:
1. \(6\ \text{s}\)
2. \(7\ \text{s}\)
3. \(9\ \text{s}\)
4. \(10\ \text{s}\)