A ball is projected horizontally from a cliff 40 m high at a speed of 40 m/s and simultaneously a ball is dropped. If the time taken by the two balls to reach the ground are respectively (taking air friction into consideration), then
(1)
(2)
(3)
(4) Depending on air friction maybe less or more than
Select the incorrect statement:
1. | It is possible to have \(\left|\frac{{d} \overrightarrow{v}}{dt}\right| = 0 \) and \(\frac{{d}|\overrightarrow{v}|}{{dt}} \neq 0 \) |
2. | It is possible to have\(\left|\frac{{d} \overrightarrow{{v}}}{{dt}}\right| \neq 0 \) and \(\frac{{d}|\overrightarrow{{v}}|}{dt}=0 .\) |
3. | it is possible to have\(\left|\frac{{d} \overrightarrow{v}}{{dt}}\right|=0\) and \(\frac{{d}|\overrightarrow{{v}}|}{dt}=0 . \) |
4. | It is possible to have \(\left|\frac{{d} \overrightarrow{{v}}}{{dt}}\right| \neq 0\) and \(\frac{{d} \overrightarrow{{v}}}{{dt}} \neq 0 \) |
A projectile is fired horizontally from the top of a tower. The time after which the instantaneous velocity will be perpendicular to the initial velocity is (neglect air resistance) :
(1)
(2)
(3)
(4) It will never be perpendicular at any instant
A particle of mass \(2\) kg is moving in a circular path with a constant speed of \(10\) m/s. The change in the magnitude of velocity when a particle travels from \(P\) to \(Q\) will be: [assume the radius of the circle is \(10/\pi^2]\)
1. | \(10 \sqrt{3} \) | 2. | \(20 \sqrt{3}\) |
3. | \(10\) | 4. | \(0\) |
Uniform circular motion is an example of:
(1) Uniform motion
(2) Uniform speed
(3) Uniform acceleration
(4) Non-uniform speed
Given below are two statements:
Statement I: | The path of a projectile with respect to another projectile is a straight line. |
Statement II: | The acceleration of one projectile with respect to the other is zero. |
1. | Statement I is false but Statement II is true. |
2. | Both Statement I and Statement II are true. |
3. | Both Statement I and Statement II are false. |
4. | Statement I is true but Statement II is false. |
Given below are two statements:
Statement I: | During the projectile motion of a particle near the earth's surface, only a vertical component of its velocity changes. |
Statement II: | Acceleration due to gravity near the earth's surface is in a vertically downward direction. |
1. | Statement I is false but Statement II is true. |
2. | Both Statement I and Statement II are true. |
3. | Both Statement I and Statement II are false. |
4. | Statement I is true but Statement II is false. |
Given below are two statements:
Statement I: | Force acting on a particle in uniform circular motion is constant. |
Statement II: | Acceleration of a particle in uniform circular motion is constant. |
1. | Statement I is false but Statement II is true. |
2. | Both Statement I and Statement II are true. |
3. | Both Statement I and Statement II are false. |
4. | Statement I is true but Statement II is false. |
Given below are two statements:
Statement I: | Range for projectile motion on a horizontal plane is maximum for the angle of projection equal to 45°. |
Statement II: | The time of flight of a projectile on a horizontal plane does not depend on the horizontal component of velocity. |
1. | Statement I is false but Statement II is true. |
2. | Both Statement I and Statement II are true. |
3. | Both Statement I and Statement II are false. |
4. | Statement I is true but Statement II is false. |
Given below are two statements:
Statement I: | A body either dropped or thrown horizontally from the same height, reach the ground at the same time interval. |
Statement II: | The horizontal velocity of a particle has no effect on its vertical motion. |
1. | Statement I is false but Statement II is true. |
2. | Both Statement I and Statement II are true. |
3. | Both Statement I and Statement II are false. |
4. | Statement I is true but Statement II is false. |