Question

A child walks 5.0 meters north, then 4.0 meters east, and finally 2.0 meters south. what is the magnitude of the resultant displacement of the child after the entire walk

Answer 1

Answer:

Resultant displacement of the child is 5 m.

Explanation:

It is given that, a child walks 5.0 meters north, then 4.0 meters east, and finally 2.0 meters south.

We have to find the magnitude of displacement of the child after the entire walk. The attached figure shows entire journey of the child. Displacement of an object is equal to the shortest path covered by it. Here, AM shows the net displacement. It can be calculated using Pythagoras theorem as :

Since, AB = 5 m So, OA = 3 m and BC = OM = 4 m

$OA^2+OM^2=AM^2$

$3^2+4^2=AM^2$

⇒ AM = 5 m

Hence, the resultant displacement of the child after the entire walk is 5 m.

Answer 2

Hi, if you draw a diagram of what is actually happening you will be able to understand what is happening much easier. Also displacement means distance from the starting point not the distance traveled if you didn't know already. so |dw:1318897040544:dw| if you follow this diagram you can see how the child has walked, you can then make a triangle and work the displacement which in the case is the root of the sum of the two other sides. This is just Pythagoras a^2+b^2=c^2 2