6 A ball is thrown with speed \(u\) at an angle of \(45 ^ { \circ }\) to the horizontal from a point \(O\)
When the horizontal displacement of the ball is \(x\), the vertical displacement of the ball above \(O\) is \(y\) where
$$y = x - \frac { k x ^ { 2 } } { u ^ { 2 } }$$
6
- Use dimensional analysis to find the dimensions of \(k\)
6 - State what can be deduced about \(k\) from the dimensions that you found in part (a).