The plane tectonic theory describes the motion of the continents across the face of Earth. Measurements suggest that Africa and South America were once connected and are drifting apart at an average rate of 3cm/yr. If the two continents are now 7x10^8 cm apart, how long has this drift been taking place?
time=distance/velocity= 7E8/3 years
To find out how long the drift between Africa and South America has been taking place, we can use the formula:
Time = Distance / Rate
Given:
The distance between Africa and South America = 7x10^8 cm
The rate of drifting apart = 3 cm/yr
Substituting the values into the formula, we have:
Time = (7x10^8 cm) / (3 cm/yr)
To divide by a fraction, we can multiply by its reciprocal. So, we can convert the rate into a fraction:
Time = (7x10^8 cm) * (1 yr/3 cm)
Next, we can simplify the expression:
Time = (7x10^8 cm) * (1/3) * (yr/1 cm)
= (7x10^8 cm) * (1/3) * (1 yr/1 cm)
Now, let's multiply the numbers:
Time = (7/3) * (10^8/1) * (1/1) yr
= (7/3) * (10^8) yr
Finally, evaluating the expression:
Time = (7/3) * (10^8) yr
≈ 23.3 × 10^8 yr
≈ 2.33 × 10^9 yr
Therefore, the drift between Africa and South America has been taking place for around 2.33 billion years.