As shown in Exercise 68, a formula that can be used to determine the distance of a piston with respect to the crankshaft for a 1937 John Deere B engine is s(θ) = 2.625 cos(θ) + 2.625(15 + cos² θ)^1/2, where s is measured in inches and θ in radians. θ

(a) Given that the angle θ is changing with respect to time, that is, it is a function of t, use the chain rule to find the derivative of s with respect to t, ds/dt.
(b) Use part (a), with θ = 4.944 and dθ/dt = 1340 rev per minute, to find the maximum velocity of the engine. Express your answer in miles per hour.