A advantage is less car accidents and a disadvantage is, in order to keep the roads clear of ice is a chemical. Like salt. Which is bad for the animals.
Answer:

Explanation:
Temperature of the house, 
Convert to rankine, 
Heat is extracted at 40°F i.e 
Calculate the coefficient of performance of the heat pump, COP

The minimum power required to run the heat pump is given by the formula:
...............(*)
Where the heat losses from the house, 
Substituting these values into * above

Answer
• Improving the environmental performances
• Developing Green Mining technology
Explanation
The effect to the environment caused by opal mining are; impact on soils and geology, clearing of native vegetation disrupting flora and fauna, change in land use and effects of air quality.
Opal mining is currently examining environmental impacts and adopting measures that mitigate the impacts making the process less destructive to the environment.
With the current commitment to sustainability, opal companies are investing funds for Green Mining as a positive way to impact the environment before and after mining.
a) 1.57 m/s
The sock spins once every 2.0 seconds, so its period is
T = 2.0 s
Therefore, the angular velocity of the sock is

The linear speed of the sock is given by

where
is the angular velocity
r = 0.50 m is the radius of the circular path of the sock
Substituting, we find:

B) Faster
In this case, the drum is twice as wide, so the new radius of the circular path of the sock is twice the previous one:

At the same time, the drum spins at the same frequency as before, therefore the angular frequency as not changed:

Therefore, the new linear speed would be:

And substituting,

So, we see that the linear speed has doubled.
Answer:
period of oscillations is 0.695 second
Explanation:
given data
mass m = 0.350 kg
spring stretches x = 12 cm = 0.12 m
to find out
period of oscillations
solution
we know here that force
force = k × x .........1
so force = mg = 0.35 (9.8) = 3.43 N
3.43 = k × 0.12
k = 28.58 N/m
so period of oscillations is
period of oscillations = 2π ×
................2
put here value
period of oscillations = 2π ×
period of oscillations = 0.6953
so period of oscillations is 0.695 second