Your position at time , relative to the stop line:

The Porsche's position:

a. You pass the Porsche immediately after the time it takes for :

at which point you both will have traveled 7.8 m from the stop line.

b. The equation in part (a) has two solutions. The Porsche passes you at the second solution of about , at which point you both will have traveled 29 m.

c. At time , the Porsche is moving at velocity

so that at the moment it passes you, its speed is 13 m/s, which is about 46.8 km/h and below the speed limit, so neither of you will be pulled over.

**Answer:**

A Chinese Geomancer

**Explanation:**

The compass was invented in China during the Han Dynasty between the 2nd century BC and 1st century AD where it was called the "south-governor" or "South Pointing Fish" (sīnán 司南). The magnetic compass was not, at first, used for navigation, but for geomancy and fortune-telling by the Chinese.

However, it is believed **Flavio Gioia** first invented the refined compass, and a monument has been erected in Almafi Italy to honor his invention. The magnetic compass was probably developed by combining the wind rose and the lodestone. From this device it is supposed the compass rose evolved.

**Answer:**

Total: 200 meters, Displacement: 100 meters South

**Explanation:**

First, add up the meters traveled to get the total distance.

50m + 150m = 200m

Lastly, displacement is the shortest distance from the initial position to the final position. The person first walked 50 meters north but then traveled 150 meters south. Therefore, their displacement was 100 meters south.

50m - 150m = -100m

(Note: Directions are vectors. North and East are positive vectors while South and West are negative)

As you increase the temperature, the matter begins to expand. Due to this, the distance between matter particles decreases and they are no more compact. Hence, density decreases.