Explanation:
Given
Worker started from a point 50 from entrance. The worker pushes it away from the entrance at a speed of 1 m/s for 10 s that is there is no acceleration for 10 s as speed is constant.
Distance covered in this time is given by
It is stopped for 5 s and then starts moving towards entrance with a speed of 2 m/s for 20 s. Also, there is no acceleration.
distance traveled in this time
As, distance cannot shown negative. It is shown in increasing manner.