Which one of the following is not one of the definitions of reduction? A. Reduction is the loss of oxygen from a substance.
B. Reduction is the addition of hydrogen to a substance.
C. Reduction is the gain of electrons by a substance.
D. Reduction is the loss of electrons from a substance.

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.

answer by yourhope:

how do models compare to real-world objects?

d. most models represent a real-world object in a simpler way.

: )

the answer is barium and copper bromide