Answer:
The total time of the projectile, is. t = 12.43 s
Step-by-step explanation:
Given data,
The height from which the object is projected, h = 45 m
The initial velocity of the projectile, v = 30 m/s
The time of flight of the projectile to attain maximum height,
t₁ = u/g
= 30 / 9.8
= 3.06 s
The maximum height of the projectile,
hₓ = u²/2g
= 30²/ (2 x 9.8)
= 45.92 m
To find the time taken by the projectile to reach the ground from hₓ, using the II equation of motion.
s = ut₂ + ½ gt₂²
t₂ = √(2s/g) (∵ u = 0 at hₓ)
= √(2 x 45.92 / 9.8)
= 9.37 s
Therefore the total time of the projectile,
t = t₁ + t₂
t = 3.06 s + 9.37 s
= 12.43 s
Hence, the total time of the projectile, is. t = 12.43 s