Answer:
The answer is 5.1852 cm/yr
.
Explanation:
In order to calculate the full seafloor spreading rate in cm/yr, we have to first calculate the half-spreading rate which can be done by simply dividing the given distance (in cm) by time (yr); after calculating the half-spreading rate, we will double it and get the full seafloor spreading rate, thus:
Distance = 3,500 km = 3,500 × 100,000 cm = 350,000,000 cm
Time = 135,000,000 years
The half-spreading rate = distance ÷ time = 350,000,000 ÷ 135,000,000 = 2.5926 cm/yr
.
Therefore, the full seafloor spreading rate = 2.5926 cm/yr × 2 = 5.1852 cm/yr.