DieselShip's Online Content Library

Q7) The cost, £C per 10 metres, of laying a pipeline of cross - sectional area, x m², is given by

C = 2000 x + 500/x

Calculate EACH of the following for the pipeline:

(i) the cross - sectional area which minimises the cost per 10 metres; (8)

(ii) the minimum cost per 10 metres. (2)

(b) When a flywheel rotates through an angle of Ɵ radians in t seconds, its angular velocity is given by dƟ/dt radian/s, and its angular acceleration is given by (d^2 Ɵ)/dt² radian/s².

For a certain flywheel θ = 21t - 1.5t².

Determine EACH of the following for this flywheel:

(i) the angular velocity when t = 5; (3)

(ii) the time that elapses before the angular velocity is zero; (2)

(iii) the angular acceleration. (1)