A dog runs 30 feet to the north then 5 feet to the south what is the displacement of the dog

To look for displacement, just draw a vector from your beginning stage to your last position and settle for the length of this line. So we begin by drawing a line to the north which is 30 ft, since it is north, the line is going up, then it move 5 ft to the south, so put a line going down, so we are in 25 ft, North so that would be the answer.

The initial displacement=d1 = 30 feet North

d2 = - 5 feet south

we take d2 as negative because we treat south direction as negative

so the net displacement = d1+d2

net displacement = - 5+30

net displacement=25

so the net displacement = 25 feet North.