Question

“An object that is in flight after being thrown or projected is called a projectile”.

1. Which of the following remains constant throughout the motion of the projectile?

(i) Vertical component of velocity

(ii) Horizontal component of velocity

2. Derive an expression for maximum range of a projectile.

3. Show that range of projection of a projectile for two angles of a projection a and (3 is same where α + β = 90°.

Answer 1

1. (ii)

2. If we neglect the air resistance, the horizontal velocity (ucosθ) of projectile will be a constant. Hence the horizontal distance (R) can be found as

R = horizontal velocity × time of flight

3. Range of projectile R = u2sin2θg

Case – 1

at angle α,

R_α = \(\frac{u^2sin^2α}{G}\) ____(1)

Case – 2

at an angle β,

From (1) and (2), we get
R_α = R_β