Question

a particle is projected at an angle 30 degree with the horizontal with speed 20 m/s. how high will it strike a wall 8(3)^1/2 m away from point of projection
g=10m/s^2

Answer 1

Given :

A particle is projected at an angle 30 degree with the horizontal with speed 20 m/s

g = 10 m/s²

To Find :

How high will it strike a wall 8√3 m away from point of projection

Solution :

•It is given that

initial speed (u) = 20m/s

Angle of projection (a) = 30°

Distance of wall (x) = 8√3 m

•Trajectory is actual path travelled by the particle

• Equation of trajectory is relation between x&y coordinates of a projectile at any time t

•So , Equation of trajectory is

y = xtan(a) - (g x²)/2u²cos²a

•For x = 8√3 m

y = 8√3.tan30°

- 10(8√3)²/2(20)²cos²(30°)

y = 8√3(1/√3) - 10(192)/800(√3/2)²

y = 8 - (1920)/(800.3/4)

y = 8 - 1920/600

y = 8 - 3.2

y = 4.8 m

•Hence , Projectile will be 4.8m high when it strikes the wall 8√3 m away