Answer:
Step-by-step explanation:
The rock will hit the surface when its height equals zero.
t^2-8t-10=0
t^2-8t=10
t^2-8t+16=10+16
(t-4)^2=26
t-4=+(26^(1/2))
t=4+(26^(1/2))
t=9.1s
Given:
The radius of the base of the given cone = 5 cm
The slant height of the cone = 19 cm
To find the surface area of the given cone.
Formula
The surface area pf the given cone is,
where, r be the radius and
l be the slant height.
Now,
Taking, r = 5, l = 19 and π = 3.14 we get,
sq cm
or, sq cm
or, sq cm
Rounding off to the nearest square centimeter, we get;
Hence,
The surface area of the cone is 377 sq cm.
