Solution of task 9.1.7 from the collection of Kepe OE

Solution of task 9.1.7 from the collection of Kepe OE

9.1.7
The vertices A and B of the triangle are always on the axes Oy and Ox at the time of the motion. Determine the angle of rotation? At time t1 = 2 s, if the vertex B from the position XB (0) = 2 m began to mix with a constant velocity vB = 0.5 m / s; Length AB = 4 m. (Answer 0,846)