Maths
posted by Gabrielle .
A swing 5 metres long swings through a vertical angle of 50 degrees. Through what vertical distance does the seat rise in going from its lowest position to its highest?

At the lowest point, the swing is 5m below the support.
At the halfvertical angle of 50, the swing is 5m*cos(25°) below the support.
So the vertical distance
= 5m*(1cos(25°)
Your calculator will give you the approximation to the exact answer.