A helicopter moving vertically upwards releases a packet when it is at a certain height above the ground. The packet initially moves upwards for a time \(t_1\) and then falls downwards for a time \(t_2\) until it reaches the ground. Then:
1. | \(t_1<t_2\) | 2. | \(t_1=t_2\) |
3. | \(t_1>t_2\) | 4. | Data insufficient |
A ball is thrown vertically downwards with a velocity of \(20\) m/s from the top of a tower. It hits the ground after some time with the velocity of \(80\) m/s . The height of the tower is: (assuming \(g = 10~\text{m/s}^2)\)
1. | \(340\) m | 2. | \(320\) m |
3. | \(300\) m | 4. | \(360\) m |
If a particle has negative velocity and negative acceleration, its speed:
1. | increases | 2. | decreases |
3. | remains the same | 4. | zero |
Suppose you are riding a bike with a speed of \(20\) m/s due east relative to a person \(A\) who is walking on the ground towards the east. If your friend \(B\) walking on the ground due west measures your speed as \(30\) m/s due east, find the relative velocity between two reference frames \(A\) and \(B\):
1. | \(A\) with respect to \(B\) is \(5\) m/s towards the east. | The velocity of
2. | \(A\) with respect to \(B\) is \(5\) m/s towards the west. | The velocity of
3. | \(A\) with respect to \(B\) is \(10\) m/s towards the east. | The velocity of
4. | \(A\) with respect to \(B\) is \(10\) m/s towards the west. | The velocity of
A particle is moving along the \(x\)-axis such that its velocity varies with time as per the equation \(v = 20\left(1-\frac{t}{2}\right)\). At \(t=0\) particle is at the origin. From the following, select the correct position \((x)\) - time \((t)\) plot for the particle:
1. | 2. | ||
3. | 4. |
Starting from rest, a car accelerates uniformly at the rate of \(1~\text{m/s}^2\) for some time, then decelerates uniformly at the rate of \(2~\text{m/s}^2\) and finally comes to rest after a journey of \(1\) minute. The maximum possible speed of the car during this journey is:
1. \(10\) m/s
2. \(20\) m/s
3. \(30\) m/s
4. \(40\) m/s
The velocity \(v\) of an object varies with its position \(x\) on a straight line as \(v=3\sqrt{x}.\) Its acceleration versus time \((a\text-t)\) graph is best represented by:
1. | 2. | ||
3. | 4. |
Two stones are thrown vertically up simultaneously with different velocities. Which of the following graphs represents the relative separation \((\Delta y)\) between them as a function of time \((t)\)?
1. | 2. | ||
3. | 4. |
A particle starts from rest (with constant acceleration) and acquires velocity \(20\) m/s in \(5\) s. The distance travelled by the particle in the next \(2\) s will be:
1. | \(50\) m | 2. | \(48\) m |
3. | \(100\) m | 4. | \(150\) m |
The graph below shows position as a function of time for two trains running on parallel tracks.
Which of the following statements is true?
1. | At time \(t_B \) both the trains have the same velocity |
2. | Both the trains have the same velocity at some time after \(t_B \) |
3. | Both the trains have the same velocity at some time before \(t_B \) |
4. | Both the trains have the same acceleration |