A doubly tethered model airplane of mass 1.0 kg is attached to a vertical rod by two very light strings that are 2.0 each in length. the airplane and the the strings rotate in a horizontal circleabout the rod with both the strings remaining taut.The attachment points of the strings are also separated by 2.0 m If the tension in the upper string is 39.2 N. Calculate

Question

A doubly tethered model airplane of mass 1.0 kg is attached to a vertical rod by two very light strings that are 2.0 each in length. the airplane and the the strings rotate in a horizontal circleabout the rod with both the strings remaining taut.The attachment points of the strings are also separated by 2.0 m If the tension in the upper string is 39.2 N. Calculate
a)the tension in the lower string.Is it likely to be less or more than the tension in the upper string?
b)the steady speed of the ball as it undergoes circular motion.

bobpursley · Answer

If the tensions were unequal, wouldn't there be a bending moment causing the model to twist? The speed of the plane (not ball) causes centripetal force, which has to equal the sum of tensions.