What is a contour interval?
a. a loop formed by contour lines that indicates a peak or depression
b. the elevation difference between two adjacent contour lines
c. an imaginary line that joins points of equal elevation
d. the degree of a slope's steepness

b. the elevation difference between two adjacent contour lines

d. the degree of a slope's steepness

a contour interval is, in fact the degree of a slope's steepness.

hope this !

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.