Answer:
7.5 m 
Explanation:
 = initial speed of the ball = 8 m/s
 = initial speed of the ball = 8 m/s 
 = angle of launch = 40° deg
 = angle of launch = 40° deg
Consider the motion along the vertical direction :
 = initial velocity along vertical direction =
 = initial velocity along vertical direction =  = 8 Sin40 = 5.14 m/s
 = 8 Sin40 = 5.14 m/s 
 = acceleration along vertical direction = - 9.8 m/s²
 = acceleration along vertical direction = - 9.8 m/s²
 = time of travel
 = time of travel 
 = vertical displacement = - 1 m
 = vertical displacement = - 1 m 
Using the kinematics equation 


 = 1.22 sec
 = 1.22 sec 
Consider the motion along the horizontal direction :
 = initial velocity along horizontal direction =
 = initial velocity along horizontal direction =  = 8 Cos40 = 6.13 m/s
 = 8 Cos40 = 6.13 m/s 
 = acceleration along vertical direction = 0 m/s²
 = acceleration along vertical direction = 0 m/s²
 = time of travel = 1.22 sec
 = time of travel = 1.22 sec
 = horizontal displacement = ?
 = horizontal displacement = ? 
Using the kinematics equation 


 = 7.5 m
 = 7.5 m