How many total atoms in 3CuSO4

18

Explanation:

Element  Symbol   no of Atoms

Copper           Cu                3

Sulfur            S                3

Oxygen           O                  12

                                              18 = total

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)