A ball is thrown vertically upwards. Then the velocity-time \((v\text-t)\) graph will be:
1. | 2. | ||
3. | 4. |
A person standing on the floor of an elevator drops a coin. The coin reaches the floor in time if the elevator is moving uniformly and time if the elevator is stationary. Then:
1. | \(t_1<t_2 \) or \(t_1>t_2 \) depending upon whether the lift is going up or down. |
2. | \(t_1<t_2 \) |
3. | \(t_1>t_2 \) |
4. | \(t_1=t_2 \) |
The displacement time graph of a moving particle is shown in the figure below. The instantaneous velocity of the particle is negative at the point:
1. | D | 2. | F |
3. | C | 4. | E |
A particle moves along a path \(ABCD\) as shown in the figure. The magnitude of the displacement of the particle from \(A\) to \(D\) is:
1. m
2. \(10\) m
3. m
4. \(15\) m
For the following acceleration versus time graph, the corresponding velocity versus displacement graph is:
1. | 2. | ||
3. | 4. |
A stone falls freely from rest from a height \(h\) and it travels a distance of \(\frac{9 h}{25}\) in the last second. The value of \(h\) is:
1. | \(145\) m | 2. | \(100\) m |
3. | \(122.5\) m | 4. | \(200\) ms |
The initial velocity of a particle is \(u\) (at \(t=0\)) and the acceleration \(f\) is given by \(at\). Which of the following relation is valid?
1. \(v = u + a t^{2}\)
2. \(v = u + a \frac{t^{2}}{2}\)
3. \(v = u + a t\)
4. \(v= u\)
Which of the following four statements is false?
1. | A body can have zero velocity and still be accelerated. |
2. | A body can have a constant velocity and still have a varying speed. |
3. | A body can have a constant speed and still have a varying velocity. |
4. | The direction of the velocity of a body can change when its acceleration is constant. |
Two cars \(A\) and \(B\) are travelling in the same direction with velocities \(v_1\) and \(v_2\) \((v_1>v_2).\) When the car \(A\) is at a distance \(d\) behind car \(B\), the driver of the car \(A\) applied the brake producing uniform retardation \(a\). There will be no collision when:
1. \(d < \frac{\left( v_{1} - v_{2} \right)^{2}}{2 a}\)
2. \(d < \frac{v_{1}^{2} - v_{2}^{2}}{2 a}\)
3. \(d > \frac{\left(v_{1} - v_{2}\right)^{2}}{2 a}\)
4. \(d > \frac{v_{1}^{2} - v_{2}^{2}}{2 a}\)
Assertion (A): | Displacement of a body may be zero when distance travelled by it is not zero. |
Reason (R): | The displacement is the longest distance between initial and final position. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | Both (A) and (R) are False. |