Two projectiles projected with the same speed at angles and (90° - ) from the same point, then is equal to: (where symbols have their usual meanings)
1.
2.
3.
4.
A projectile is projected from the ground with speed 20 m/s at an angle 30° with vertical. The radius of curvature of the path of a projectile, when velocity makes 30° with horizontal is (g = 10 m/)
(1) 8.5 m
(2) 15.4 m
(3) 26.2 m
(4) 32.6 m
A projectile is projected with speed u at an angle of 30° with the vertical from the ground. The angle between the acceleration of the projectile and its velocity at the time of striking the horizontal ground is:
(1) 30°
(2) 60°
(3) 45°
(4) 0°
Which of the following statements is incorrect?
1. | The average speed of a particle in a given time interval cannot be less than the magnitude of the average velocity. |
2. | It is possible to have a situation \(\left|\frac{d\overrightarrow {v}}{dt}\right|\neq0\) but \(\frac{d\left|\overrightarrow{v}\right|}{dt}=0\) |
3. | The average velocity of a particle is zero in a time interval. It is possible that instantaneous velocity is never zero in that interval. |
4. | It is possible to have a situation in which \(\left|\frac{d\overrightarrow{v}}{dt}\right|=0\) but \(\frac{d\left|\overrightarrow{v}\right|}{dt}\neq0\) |
A man is walking on a horizontal road at a speed of \(4~\text{km/hr}.\) Suddenly, the rain starts vertically downwards with a speed of \(7~\text{km/hr}.\) The magnitude of the relative velocity of the rain with respect to the man is:
1. \(\sqrt{33}~\text{km/hr}\)
2. \(\sqrt{65}~\text{km/hr}\)
3. \(8~\text{km/hr}\)
4. \(4~\text{km/hr}\)
A particle of mass 6 kg moves with an initial velocity of m/s. A constant force of N is applied to the particle. Initially, the particle was at (0, 0). The x-coordinate of the particle, when its y-coordinate again becomes zero is given by
(1) 6.0 m
(2) 12.8 m
(3) 8 m
(4) 25.6 m
In a uniform circular motion:
(1) Velocity and acceleration remain constant.
(2) Kinetic energy remains constant.
(3) Speed and acceleration changes.
(4) Only velocity changes, acceleration remains constant.
If a body is accelerating, then:
1. | it must speed up. |
2. | it may move at the same speed. |
3. | it may move with the same velocity. |
4. | it must slow down. |
Compared to an ideal projectile motion under gravity, which of the following is incorrect regarding another projectile motion in which air friction is also considered?
1. | The time of flight decreases. |
2. | Decrease in the horizontal component of velocity continuously. |
3. | The angle with horizontal is less at the time of striking the ground compared to the angle of projection with horizontal. |
4. | The angle with the vertical is less at the time of striking the ground with respect to the angle of projection with vertical. |
Two balls are projected to acquire same range with the same initial speed u but at different angles of projection. If maximum height acquired by balls are , then () is: (angle of projection of one projectile is )
(1)
(2)
(3)
(4) tan