Question

4. Say Russell Wilson has to throw Doug Baldwin a pass 50 meters in 2 seconds. Assume no air or spin of the ball and use g= 10 m/s2. Use 1.8 meters for the ball height both right after it is thrown, and right before it is caught. (a) What is the initial speed Wilson has to throw the ball at? and (b) what is the angle he has to throw the ball at? У Doug Baldwin Russell Wilson X 2 neglect air, neglect spin 1

Answer 1

suppose initial speed

in x =u_x and in y = u_y

in x-direction

X = U_x *t

50 = U_x *2

u_x = 50/2 = 25 m/s

in Y direction

Sy = u_y *t + 1/2*a_y *t²

0 = u_y *2 + 1/2* -10*2^2

u_y *2 = 20

u_y = 20/ 2 = 10 m/ s

so intial speed = sqrt( u_x ^2+  u_y^2 ) = sqrt( 25^2+10^2) =26.925824 m/s

initial speed =26.925824 m/s

tanθ = u_y /u_x   = 10/25 = 0.4

θ = tan^-1(0.4) = 21.801 degree

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