If there are 20 earthworms in a garden that covers 5 square meters, what is the population density of the earthworms? a. 20 earthworms b. 4 c. 100 earthworms per square meter d. 4 earthworms per square meter

I think, I do think.. that it is D.

Wouldn't it be simple to divide 5 from 20, that would equal 4.

4 earthworms per square meter.

d is the correct answer

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.