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) Time of flight decreases.
(2) The decrease in the horizontal component of velocity continuously.
(3) Angle with horizontal is less at the time of striking the ground compared to the angle of projection with horizontal.
(4) Angle with 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
At the highest point of trajectory in the ground to the ground projectile, the angle between gravitational acceleration and momentum is
(1) 30°
(2) 45°
(3) 90°
(4) Data insufficient
A particle revolves in a horizontal circle with decreasing velocity. The angle between instantaneous velocity and instantaneous acceleration of the particle at an instant is
(1) < 90°
(2) > 90°
(3) = 90°
(4) 90°
Two projectiles are thrown horizontally from a high cliff in the opposite direction with the same speed 20 m/ s simultaneously. At what time velocities of both particles become perpendicular?
(1) 2 s
(2) 2 s
(3) 4 s
(4) 4 s
The equation of the trajectory of a projectile is given as . The range of the projectile is:
(1) 1 m
(2) 32 m
(3) 16 m
(4) 48 m
A cannon can give a maximum speed of 70 m/s to bombs. The maximum distance up to which cannon projects a bomb is (g = 10 m/)
(1) 490 m
(2) 245 m
(3) 100 m
(4) 300 m