A ball is kicked at an angle of 30° with the vertical if the . . .

Question : A ball is kicked at an angle of 30° with the vertical if the horizontal component of its velocity is 19.6 m/s. Find the maximum height and horizontal range.


Doubt by Jaskirat

Solution : 
θ= 90
°-30° 
θ= 60°

Horizontal Component of velocity 
ux = 19.6 m/s
ucos
θ = 19.6 
cos60° =19.6
u(1/2) = 19.6
u = 19.6×2
u = 39.2 m/s

Maximum Height attained by the Projectile
Hmax = u²sin²
θ/2g
= (39.2)²sin²(60°)/[2×9.8]
= [39.2×39.2×(√3/2)²]/[2×9.8]
[39.2×39.2×(3/4)]/[2×9.8]
[39.2×39.2×3]/[4×2×9.8]
= 58.8 m

Horizontal Range of Projectile
 = u²sin2θ/g
 = [(39.2)²sin(2×
60°)]/9.8
 = [39.2×39.2×sin120
°]/9.8
 = 
[39.2×39.2×(√3/2)]/9.8
 = 
[39.2×39.2×√3)]/[2×9.8]
 = 78.4√3
 = 78.4×1.732
 = 135.788
 = 135.79 m

Hence, maximum height is 58.8 m and Range is 135.79 m