โจทย์ข้อนี้ทำไงอะ

The boom of a fire truck raises a fireman (and his equipment—total weight 290lbf) 30ft into the air to fight a building fire.  

(a) Using unity conversion ratios, calculate the work done by the boom on the fireman in units of Btu.
(b) If the useful power supplied by the boom to lift the fireman is 3.60hp, estimate how long it takes to lift the fireman.