KinematicsHard
Question
Particles are projected from the top of a tower with same speed at different angles as shown. Which of the following are True ?


Options
A.All the particles would strike the ground with (same) speed.
B.All the particles would strike the ground with (same) speed simultaneously.
C.Particle 1 will be the first to strike the ground.
D.Particle 1 strikes the ground with maximum speed.
Solution

Let final vel be V2
Now v2x = horizontal component of velocity
V2 x = Vcos θ & V22y = (V sin θ)2 + 2 (− g) (− H)
∴ V22y = V2 sin2θ + 2 gH
⇒ V22 = V22x + V22y
= (V cos θ )2 + [V2 sin2θ + 2gH]
V22 = V2 + 2 gH
i.e., V =
This magnitude of final velocity is independent on θ
⇒ all particles strike the ground with the same speed.
i.e., ′A′ is correct.
In vertical motion
The highest velocity (initial) along the direction of displacement is possessed by particle (1). Hence particle (1) will reach the ground earliest. [since ay and sy are same for all]
i.e., ′C′ is correct
Create a free account to view solution
View Solution FreeMore Kinematics Questions
A body of mass ′m′ is taken from the earth′s surface to the height equal to twice the radius (R) of th...A particle is moving in x - y plane at 2 m/s along x - axis. 2 seconds later, its velocity is 4 m/s in a direction makin...A small ball rolls of the top of a stairway horizontally with a velocity of 4.5 m s-1. Each step is 0.2 m high and 0.3 m...A ball is thrown from bottom of an incline plane at an angle a from the inclined surface up the plane. Another ball is t...A river is flowing east to west at a speed of 5 m / min. A on south bank of river, capable of swimming 10m/min in still ...