# OCR A Level: Mechanics 2 - Projectile Motion [June 2008 Q4]

A golfer hits a ball from a point $$O$$ on horizontal ground with a velocity of $$35\text{ms}^{-1}$$ at an angle of $$\theta$$ above the horizontal. The horizontal range of the ball is $$R$$ and the time of flight is $$t$$ seconds.

$$(\text{i})$$ Express $$t$$ in terms of $$\theta$$, and hence show that $$R=125 \sin 2 \theta$$.

The golfer hits the ball so that it lands $$110 \text{m}$$ from $$O$$.

$$(\text{ii})$$ Calculate the two possible values of $$t$$.

Input the sum of the two values of $$t$$, correct to 3 significant figures

×