The amide formed in the reaction of 3-ethylbenzoic acid and dimethylamine is

-

3-Ethyl-N,N-dimethylbenzamide.

Explanation: -

In the first step the nitrogen lone pair attacks the carbonyl carbon.

Then a OH becomes water molecule by protonation and leaves.

Final step involves proton loss to form amide.

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.

14 days is the half-life of phosphorus-32