first we make a U turn and travel towards home in t = 20 s
so the distance of home from initial position is


Now after picking up the book we travel back with speed 20 m/s
so again after t = 20 s the displacement is given as

so the net displacement is given as


so it will be displaced by total displacement 200 m
Because they perform specific tasks repeatedly throughout your program, as needed
<span>During
adverse weather conditions such as rain or fog, drivers should take
action accordingly by turning on their headlights, slowing down and
increasing following distance. Adverse weather means that you are driving in difficult and dangerous conditions. Increasing following distance will help you to maintain safe driving and avoid tailgating. </span>