Question

Olivia places her pet frog on a line to observe the frog’s motion. The line is divided into sections that measure 1 centimeter each. The frog begins at 0, moves 18 centimeters forward, moves 6 centimeters backward, and then 12 centimeters backward. What is the frog’s displacement?

Answer 1

Motion forward is :

= 18cm

Motion backward is :

= 12 + 6 = 18cm

The displacement is given by the negative forces plus the positive forces.

The motion backwards is negative and the motion forward is positive.

We can analyze this as follows.

Backward = - 18

Forward = +18

Now adding the two :

18 - 18 = 0

The displacement is zero.