The length of a wave so, therefore its D.
Some substances look alike and the density can help you determine which is which. It also helps to tell which is heavier than the other.
A theory is a system of ideas that isn't exactly proven to be true fully. A law is a description of whatever scientific phenomena you're studying. All you need to know is a law describes, and a theory explains.
If it takes 1 year for this crab to travel 5,70km
Then, it will takes approximatly 1000/5,70 = 175 years to travel 1000 km
