11. If a 1 kg spear is thrown at 10 m/s and gets imbedded into a 9 kg wooden box that was at rest, how fast does the wooden box and embedded spear move after the collision?

What is the composition, in atom percent, of an alloy that consists of 4.5 wt% pb and 95.5 wt% sn? the atomic weights for pb and sn are 207.19 g/mol and 118.71 g/mol, respectively.(a) 2.6 at% pb and 97.4 at% sn(b) 7.6 at% pb and 92.4 at% sn(c)97.4 at% pb and 2.6 at% sn(d) 92.4 at% pb and 7.6 at% sn

Why do cells appear different in distilled water than they do in 10% salt water?

Iwould appreciate if someone could me.