College Physics with MasteringPhysics 7th Edition by Jerry Wilson,Anthony Buffa,Bo Lou

تمرين 116

A hot-air balloon ascends at a constant rate. (a)The weight of the balloon does (1) positive work, (2) negative work, (3) no work. Why (b) A hot-air balloon with a mass of 500 kg ascends at a constant rate of 1.50 m/s for 20.0 s. How much work is done by the upward buoyant force (Neglect air resistance.)