A body \(A\) moves with a uniform acceleration \(a\) and zero initial velocity. Another body \(B\), starts from the same point and moves in the same direction with a constant velocity \(v\). The two bodies meet after a time \(t\). The value of \(t\) is:
1. \(\dfrac{2v}{a}\)
2. \(\dfrac{v}{a}\)
3. \(\dfrac{v}{2a}\)
4. \(\sqrt{\dfrac{v}{2a}}\)
A particle moves along \(x\)-axis in such a way that its coordinate \(x\) varies with time \(t\) according to the equation \(𝑥 = ( 2 − 5 𝑡 + 6 𝑡^ 2 ) \) m. The initial velocity of the particle is:
1. \(–5\ \text{m/s}\)
2. \(6\ \text{m/s}\)
3. \(–3\ \text{m/s}\)
4. \(3\ \text{m/s}\)
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. \(aT\)
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. \(275\ \text{m}\)
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. \(4\text{ m/s}^2\)
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. \(𝑎
∝
𝑡
\)
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
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