Answer :
Answer:
ball rise height is 19.34 m
Explanation:
given data
speed = 11.2 m/s
angle = 51°
to find out
How high does the ball rise
solution
we take here velocity vector as x and y component in horizontal and vertical direction
velocity (x) = v cos 51
velocity (y) = v sin 51
and ratio between these component is
[tex]\frac{Vy}{Vx} =\frac{vsin60}{vcos60}[/tex]
Vy = tan51 Vx
Vy = 1.23 Vx
we consider here speed v is relative to teacher
and here no motion in x refer to teacher so V will be 0
so equation of motion
V = Vx + v = 0
Vx = -v
Vx = - 11.2 m/s
so ball thrown backward student ref is
Vref y = Vy
Vref y = 1.23 Vx
Vref y = 1.23 (-11.2)
Vref y = 13.77 m/s
and
height of ball by kinematic equation
height = [tex]\frac{v^2}{2g}[/tex]
here v is 13.77 and g = 9.8
height = [tex]\frac{13.77^2}{2(9.8)}[/tex]
height = 19.34 m
so ball rise height is 19.34 m