Answer:
1411.8 N/m
Explanation:
From Hooke's law;
F= Ke
Where
F= force on the spring
K= force constant
e = extension
But e= 8.50 × 10^-2m
F= weight = 12.0 kg × 10 = 120 N
K = F/e = 120/8.50 × 10^-2
K= 1411.8 N/m
No fire uses oxygen sparks and flammable wood or whatever you choose to burn
<span>A particular frost-free refrigerator uses about 710kWh of electrical energy per year. You are to express this amount of energy in J, kJ, & Calories.
1 year (365 days / 1 year)(24 hours / 1 day)(3600s / 1h) = 31,536,000s
710 kWh/yr (1 yr) = 710 kWh
710 x 10^3 Wh = </span>710 x 10^3(J/s)(31,536,000s)<span> = 2.24 x 10^13 J
</span>2.24 x 10^13 J = 2.24 x 10^10 kJ = 5.35 x 10^12 cal
Answer:
decibels (dB)
Explanation:
The sound intensity level is a quantity derived from the sound intensity.
The intensity of a wave is defined as the power of the source of the wave divided by the area through which the power of the wave is spread, mathematically:
where
P is the power of the source
is the surface area over which the wave spreads (assuming that the wave propagates in all directions, it corresponds to the surface area of a sphere of radius 
, where r is the distance between the source of the wave and the observer)
For sound waves, the intensity is often expressed using another unit, called decibel (dB), defined as follows:
where
is the sound intensity level in decibels
I is the intensity of the sound wave
is the threshold intensity of a sound that a person can normally hear.
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.
