A plate moving at a rate of 4 is moving toward a plate that is 10,000 km away. In how many years will the plates collide? 250 million years
2,500 years
25 thousand years
250,000 years

The plates will collide in 250 million years.

Explanation:

Earth is divided into numerous plates. All of them are in constant motion which is driven by the convection currents in the mantle. All plates move in different directions, with some moving toward each other, some moving away from each other, and some slide past each other.

In this case, we have a plate that moves toward another plate, and the other plate presumably is static (not really possible, but still). The plate that moves is moving with 4 cm per year, and the distance between the plates is 10,000 km, so in order to get a result in how many years they will collide, we need to convert the km into cm and then simply divide them by the speed of the plate.

1 m = 100 cm

1 km = 1,000 m

1,000 x 100 = 100,000 cm

100,000 x 10,000 = 1,000,000,000 cm

1,000,000,000 / 4 = 250,000,000

We get a result of 250 million, meaning that the plates will collide in 250 million years.