Each of the 4 engines of a jet airliner delivers 100,000 hp of mechanical power to the airliner when the airliner is traveling at constant altitude at a constant speed of 550 mi/h. How much mechanical power (in hp) does each engine deliver at the same thrust when the airliner is at rest on the ground

Awater balloon launcher uses an elastic band with a spring constant of 115 n/m to use thee launcher you stretch thee band back with a balloon n it the water balloons have a mass of 1.3 kg a) if you stretch the band by 0.8 m, what elastic force will the band exert? b) with the band stretched 0.8 m, how much elastic potential energy is stored in the spring? c) if you release the band, it pushes forward. what is the kinetic energy of the balloon when it reaches the natural length of the band? d) what is the speed of the balloon when it reaches the natural length of the band?