The "Giant Swing" at a county fair consists of a vertical central shaft with a number of horizontal arms attached at its upper end. (See the figure below (Figure 1) ) Each arm supports a seat suspended from a 5.00m -long cable, the upper end of which is fastened to the arm. Take R = 1.90m.

Find the time of one revolution of the swing if the cable supporting the seat makes an angle of θ = 30^o with the vertical.

Your spaceship lands on an unknown planet. To determine the characteristics of this planet, you drop a 1.50kg wrench from 7.00m above the ground and measure that it hits the ground 0.811 slater. You also do enough surveying to determine that the circumference of the planet is 6.24x10⁴km .