Answer:
Explanation:
Conduction of heat through a thick layer is governed by the following relation
Q = KA( T₂ -T₁ ) / d
K is thermal conductivity of medium ( it is earth here ) , A is surface area though which heat conducts and T₂ -T₁ is temperature difference and d is thickness of medium through which heat conducts.
k = 8 units
A = surface area= 2πrL
= 2x 3.14 x 2/12 x 100
= 104.67 ft²
T₂ -T₁ = 70 - 42
= 28 F
d = thickness
= 30 /12 ft
= 2.5 ft
Putting the given values here
Q =
= 9378.4 Btu per hour.
Answer:
d) 1/32 microgram
Explanation:
First half life is the time at which the concentration of the reactant reduced to half.
Second half reaction is the time at which the remaining concentration reduced to half or the initial concentration reduced to 1/4.
Third half life is the time at which the remaining concentration reduced to half or the initial concentration reduced to 1/8.
Forth half life is the time at which the remaining concentration reduced to half or the initial concentration reduced to 1/16.
Fifth half life is the time at which the remaining concentration reduced to half or the initial concentration reduced to 1/32.
The initial mass of the sample = 1 microgram
After 5 half-lives, the mass should reduce to 1/32 of the original.
So the concentration left = 1/32 of 1 microgram = 1/32 microgram
Answer: The chemical energy is converted to heat, light ,sound and kinematic movements.
Explanation:
An exploding firework is essentially a number of chemical reactions happening simultaneously or in rapid sequence. When you add some heat, you provide enough activation energy (the energy that kick-starts a chemical reaction) to make solid chemical compounds packed inside the firework combust (burn) with oxygen in the air and convert themselves into other chemicals, releasing smoke and exhaust gases such as carbon dioxide, carbon monoxide, and nitrogen in the process. For example, this is an example of one of the chemical reactions that might happen when the main gunpowder charge burn.
some of the chemical energylocked inside them is converted into four other kinds of energy (heat, light, sound, and the kinetic energy of movement). According to a basic law of physics called the conservation of energy.
I think the correct answer from the choices listed above is option C. The formula that would represent the speed of the Toyota would be <span>T+10 mph= 60 mph. Hope this answers the question. Have a nice day. Feel free to ask more questions.</span>