You want to create 14.0 g of copper to meld into a piece of jewelry. You
know that when copper (II) chloride reacts with aluminum, copper is a
product. How much aluminum would you need to start your reaction with
to get 14.0 g of copper? *
2Al + 3CuCl2 + 2AlCl3 + 3Cu

3.4g of Al

Explanation:

you would need to start with 3.4 g of Al

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.