Respuesta :
Answer:
=9.72 m/s
Explanation:
From the Newton's laws of motion;
x=2(v²cos∅sin∅)/g
Using geometry we see that 2 cos∅sin∅ = sin 2∅
Therefore, x= (v²sin 2∅)g, where v is the take off speed x the range and ∅ the launch angle.
Making v the subject of the formula we obtain the following equation.
v=√{xg /(sin 2∅)}
x=7.80
∅=27.0
v=√{7.8×9.8/sin(27×2)}
v=√94.485
v=9.72 m/s
The initial velocity is 9.72 m/s.
Since an athlete performs a projectile motion;
R = u^2sin2θ/g
- u = initial velocity
- θ = angle of projection
- g = acceleration due to gravity
R = u^2sin2θ/g
Rg = u^2sin2θ
u^2 =Rg/sin2θ
u = √Rg/sin2θ
u = √7.80 × 9.8/sin(2)27.0
u = 9.72 m/s
The initial velocity is 9.72 m/s.
Learn more about projectiles: https://brainly.com/question/2818076