You travel 10 m north and then stop for lunch and

continued another 30 m north. you then turn around and

travel 40 m south. what is your displacement?

Zero

Explanation:

Displacement is a vector connecting the initial position with the final position of motion of an object.

In this case, we have the following motion:

10 m north

30 m north

40 m south

If we take north as positive direction and south as negative direction, we can identify each motion using the following displacement vectors:

So, the total displacement is:

Which means that the final position of the motion corresponds to the initial position.

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.