Answer:
2.17ft/s
Step-by-step explanation:
Look at the sketch of ladder at the beginning and after 3 seconds it starts to fall,
Distance of ladder from the wall 3 seconds after ladder starts to fall = Initial distance+ Velocity× time
= 6 + 2×3
= 12ft
Use trignometry to find out the speed of the top of ladder
cosθ= 12/20
θ= 0.825 rad
tan θ= v/2
v= 2.17ft/s
Given:
A right prism has height 7½ and triangular bases with sides of length 5, 12, and 13.
To find:
The total surface area of the prism.
Solution:
We have,
Height of prism = 7½ = 7.5
Sides of triangular base are 5, 12, 13. These sides of Pythagorean triplets because
So, the base of the prism is a right triangle.
Area of a triangle is
The area of the base is equal to the area of the top, i.e., sq units.
Perimeter of the base is
The curved surface area of the prism is
Now, the total area of the prism is
Therefore, the total surface area of the triangular prism is 285 square units.
Answer: If we define 2:00pm as our 0 in time; then:
at t= 0. the velocity is 30 mi/h.
then at t = 10m (or 1/6 hours) the velocity is 50mi/h
Then, if we think in the "mean acceleration" as the slope between the two velocities, we can find the slope as:
a= (y2 - y1)/(x2 - x1) = (50 mi/h - 30 mi/h)/(1/6h - 0h) = 20*6mi/(h*h) = 120mi/
Now, this is the slope of the mean acceleration between t= 0h and t = 1/6h, then we can use the mean value theorem; who says that if F is a differentiable function on the interval (a,b), then exist at least one point c between a and b where F'(c) = (F(b) - F(a))/(b - a)
So if v is differentiable, then there is a time T between 0h and 1/6h where v(T) = 120mi/