Solution of task 15.1.7 from the collection of Kepe OE

Solution of task 15.1.7 from the collection of Kepe OE

15.1.7.
The material point M, whose mass m = 0.1 kg, slides down the arc of the circle
Radius r = 1 m with a central angle a = 90 °. Determine the work done by gravity
Point M when moving from position A to position B (Answer 0.981)