A ball is projected from the origin. The x- and y-coordinates of its displacement are given by `x = 3t and y = 4t - 5t^2`. Find the velocity of projection `("in" ms^(-1))`.

Answer

5

Explanation

`v_x = (dx)/(dt) = 3 and v_y = (dy)/(dt) = 4 - 10t = 4 - 10(0) = 4`
`v = [v_x^(2) + v_(y)^(2)]^(1//2) = [3^2 + 4^2]^(1//2) = 5ms^(-1)`.