Answer:
8.60 g/cm³
Explanation:
In the lattice structure of iron, there are two atoms per unit cell. So:
where
an and A is the atomic mass of iron.
Therefore:

This implies that:

= 
Assuming that there is no phase change gives:

= 8.60 g/m³
First do 1.6 m (how far he jumps) 9.8 m/s (what gravity is measured at) then times 2
= 31.36
Sq root = 5.6
Answer: friction is used when 2 and 2 things mix and come together but normally friction slows things down but when buttering a pan it doesnt slow down
I actually don't know. i speak english.