Place a ball within the funnel at the top and drop it with the help of ladder provided. The ball strikes the metal plate fixed at the bottom and bounces. Note down the distance of the first leap of the ball from metal plate and angle of metal plate’s position with the help of a protractor. Now change the angle of metal plate repeat the same procedure. Check for different angle positions until you reach the maximum distance.

What did you observe? 
The ball covers maximum distance when the metal plate is at the angle of 45degree.

The science behind it :
According to the law of projectile, a thrown object can attain maximum distance only when it is thrown at an angle of 45degree.