Answer: Contaminants can cause tremendous harm to a population; not only humans but entire local animal species can be devastated by poisonous drinking water. Crops and livestock can also be affected. Citizens can make prudent choices regarding natural resources and energy use. Scientists can research and create products that can reduce or eliminate unnecessary waste and pollution.
Explanation:
Answer:
It has poor tensile strength despite having high compressive strength
Explanation:
Concrete exhibits high compressive strength when used. However, it has very low compressive strength. This is the reason why concrete is normally combined with steel to make a composite building material called reinforced concrete. The steel reinforces concrete hence increasing the tensile strength in RC buildings. The end composite is durable and fireproof. Generally, the main reason why concrete is not use on its own is due to its poor tensile strength.
Answer:
7.15
Explanation:
Firstly, the COP of such heat pump must be measured that is,

Therefore, the temperature relationship, 
Then, we should apply the values in the COP.


The number of heat rejected by the heat pump must then be calculated.


We must then calculate the refrigerant mass flow rate.



The
value is 145.27 and therefore the hot reservoir temperature is 64° C.
The pressure at 64 ° C is thus 1849.36 kPa by interpolation.
And, the lowest reservoir temperature must be calculated.



the lowest reservoir temperature = 258.703 kpa
So, the pressure ratio should be = 7.15
Answer:
0.14% probability of observing more than 4 errors in the carpet
Explanation:
When we only have the mean, we use the Poisson distribution.
In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:

In which
x is the number of sucesses
e = 2.71828 is the Euler number
is the mean in the given interval.
The number of weaving errors in a twenty-foot by ten-foot roll of carpet has a mean of 0.8.
This means that 
What is the probability of observing more than 4 errors in the carpet
Either we observe 4 or less errors, or we observe more than 4. The sum of the probabilities of these outcomes is 1. So

We want P(X > 4). Then

In which









0.14% probability of observing more than 4 errors in the carpet