Answer:
It can be said to be reliable although it is not valid
Explanation:
This is because Reliability means an indicator of consistency, A measure should produce similar or the same results consistently if it measures the same quantity. So does the thermometer measures over 5days but it is not valid because it deviates from the real value
No spacecraft has been built yet that was able to absorb harmful
radiations in space, change weather conditions on Earth, or destroy
meteors and comets which might strike Earth.
We should continue to send robotic spacecrafts into space
because they help discard some myths about objects in space.
In other words, they help us learn things that we never knew before.
Answer:
The rate of change of the area when the bottom of the ladder (denoted by
) is at 36 ft. from the wall is the following:

Explanation:
The Area of the triangle is given by
where
(by using the Pythagoras' Theorem) and
is the length of the base of the triangle or the distance between the bottom of the ladder and the wall.
The area is then

The rate of change of the area is given by its time derivative


Product rule
Chain rule


In here we can identify
,
and
.
The result is then

Answer:
w = 11.211 KN/m
Explanation:
Given:
diameter, d = 50 mm
F.S = 2
L = 3
Due to symmetry, we have:



To find the maximum intensity, w, let's take the Pcr formula, we have:

Let's take k = 1
Substituting figures, we have:

Solving for w, we have:

w = 11211.14 N/m = 11.211 KN/m
Since Area, A= pi * (0.05)²
. This means it is safe
The maximum intensity w = 11.211KN/m