Answer:
The speed when it strikes the ground below is V= 157.64 m/s < -56.92º .
Explanation:
V= 150m/s
α= 55º
hi= 120m
Vy= V*sinα
Vy= 122.87 m/s
Vx= V * cos α
Vx= 86.03 m/s
h= hi + Vy * t - g*t²/2
clearing t we get the total flying time of the projectile:
t(total fly)= 26.01 sec
0= Vy - g*t
clearing t we get the maximum height time:
t(max height)= 12.53 sec
to get the fall time:
t(fall)= t(total fly) - t(max height)
t(fall)= 13.48 sec
Vy'= g* t(fall)
Vy'= 132.1 m/s
V'= √(Vx² +Vy'²)
V'= 157.64 m/s
α'= tg⁻¹ (Vy'/Vx)
α'= -56.92º
The final velocity of the projectile when it strikes the ground is 404.8 m/s.
The time taken for the projectile to travel the given height is calculated as follows;
[tex]h = v_0_yt + \frac{1}{2} gt^2\\\\-120 = (150 \times sin55)t - 0.5(9.8)t^2\\\\-120 = 122.8t - 4.9t^2\\\\4.9t^2 - 122.8 t -120 = 0\\\\t = 26 \ s[/tex]
The final velocity of the projectile when it strikes the ground is calculated as follows;
[tex]v_f = v_i + gt\\\\v_f = 150 + 26(9.8)\\\\v_f = 404.8 \ m/s[/tex]
Learn more about final velocity of projectile here: https://brainly.com/question/24949996
