In the textbook it is shown that the maximum range of a projectile is achieved w
ID: 2133345 • Letter: I
Question
In the textbook it is shown that the maximum range of a projectile is achieved when the launch angle is 45
In the textbook it is shown that the maximum range of a projectile is achieved when the launch angle is 45degree. The situation is more complicated in long jump (men's world record held by Mike Powell, USA, 8.95 m, 1991), because the human body has a smaller initial speed at larger take-off angles. The compromise between initial speed and angle is optimized for a take-off angle of about 20degree [J.Sports Sci. 23(7), p.703 (2005)]. Calculate the initial speed, v0, of a long-jumper where d=7.26 m. Assume a take-off angle of 19.9degree, an initial height of the centre-of-mass of 0.920 m, and a final height of 0.460 m.Explanation / Answer
Y = 0.460 -0.920=-0.460m
Y = tan(theta)*X - 0.5*9.8*X^2/V^2cos(theta)^2
-0.460 = 7.26*tan19.9-0.5*9.8*7.26^2/V^2cos19.9^2
V = 9.72 m/s
H = V^2*sin19.9^2/2*g
H = 0.56m
from ground h = 0.92+H= 1.48m