Assignment:
In this question, use g = 10m*s^-2.
In cricket, a fast bowler projects a ball at 40m*s^-1 from a point h m above the ground, which is horizontal, and at an angle alpha above the horizontal. The trajectory is such that the ball will strike the stumps at ground level a horizontal distance of 20 m from the point of projection.
(i) Determine, in terms of h, two possible values of tan alpha. Explain which of these two values is the more appropriate one, and deduce that the ball hits the stumps after approximately half a second.
(ii) State the range of values of h for which the bowler projects the ball below the horizontal.
(iii) In the case h - 2.5, give an approximate value in degrees, correct to two significant figures, for alpha. You need not justify the accuracy of your approximation.