Q. A 7.0×10-2-{rm kg} toy airplane is tied to the ceiling with a string. When the airplane's motor is started, it moves with a constant speed of 1.30 m/s in a horizontal circle of radius 0.47 m, Find the tension in the string.

Q. Many people mistakenly believe that the astronauts who orbit the Earth are "above gravity." Calculate g for space shuttle territory, 245 kilometers above the Earth's surface (dashed line in sketch). Earth's mass is 6 1024 kg, and its radius is 6.38 106 m (6380 km).