Question

A student walks 50 m north, stops, and then travels 32 m south. What is her displacement?

Answer 1

Her displacement = 18 m

Further explanation

Given

walks 50 m north and 32 m south

Required

displacement

Solution

Displacement shows vector motion that has magnitude and direction.

Displacement only looks at the distance between the starting point and the end point

Because it takes direction into account, a positive or negative sign is required

We determine that in vertical motion the upward direction is positive and the downward direction is negative

While the horizontal movement to the right is positive and the left has a negative sign

Students moving north (from the starting point) are moving positively by + 50 m

then moving south which means moving negative as far as -32 m

So that the displacement is

$\tt 50-32=18~m$