Joe drives his car 7 km north.he stops for lunch for 10 mins then drives 5 km south, except lunch time he took 20 mins. Calculate displacement
To calculate the displacement, we need to determine the final position of Joe relative to his starting point.
First, let's analyze Joe's movements step by step:
1. Joe drives 7 km north, which means he moves in the positive north direction.
2. After driving 7 km north, Joe stops for lunch for 10 minutes at this location. During this time, he does not move.
3. After lunch, Joe drives 5 km south. This means he moves in the negative south direction.
4. However, during this southward drive, Joe takes an extra 20 minutes. This means he also spends some additional time without moving.
Now, let's calculate Joe's final position:
Starting from Joe's initial position, which is considered the origin (0,0), he drives 7 km north, so his position is now (0, 7).
After that, he stops for 10 minutes, neither moving north nor south. So his position remains (0, 7).
Next, Joe drives 5 km south, which brings him to (0, 7 - 5) = (0, 2).
Lastly, during this southward drive, he takes an extra 20 minutes. This means he stays at this position for 20 minutes longer.
Therefore, Joe's final position, considering time and distance, is still (0, 2).
To calculate the displacement, we need to determine the straight-line distance between Joe's starting position and his final position.
In this case, the displacement is |final position - initial position| = |(0, 2) - (0, 0)| = |(0, 2)|.
Using the Pythagorean theorem, the displacement can be calculated as √(0^2 + 2^2) = √(0 + 4) = √4 = 2 km.
So, the displacement of Joe's car is 2 km.