Answer:
A substance made of two or more types of atoms
Explanation:
Answer:
225 N
Explanation:
"Below the horizontal" means he's pushing down at an angle.
Draw a free body diagram of the box. There are three forces: normal force N pushing up, weight force mg pulling down, and the applied force F at an angle θ.
Sum of forces in the y direction:
∑F = ma
N − mg − F sin θ = 0
N = F sin θ + mg
Plug in values:
N = (50 N) (sin 30°) + (20.0 kg) (10 m/s²)
N = 225 N
Answer:
The solution to the question above is explained below:
Explanation:
For which solid is the lumped system analysis more likely to be applicable?
<u>Answer</u>
The lumped system analysis is more likely to be applicable for the body cooled naturally.
<em>Question :Why?</em>
<u>Answer</u>
Biot number is proportional to the convection heat transfer coefficient, and it is proportional to the air velocity. When Biot no is less than 0.1 in the case of natural convection, then lumped analysis can be applied.
<u>Further explanations:</u>
Heat is a form of energy.
Heat transfer describes the flow of heat across the boundary of a system due to temperature differences and the subsequent temperature distribution and changes. There are three different ways the heat can transfer: conduction, convection, or radiation.
Heat transfer analysis which utilizes this idealization is known as the lumped system analysis.
The Biot number is a criterion dimensionless quantity used in heat transfer calculations which gives a direct indication of the relative importance of conduction and convection in determining the temperature history of a body being heated or cooled by convection at its surface. In heat transfer analysis, some bodies are observed to behave like a "lump" whose entire body temperature remains essentially uniform at all times during a heat transfer process.
Conduction is the transfer of energy in the form of heat or electricity from one atom to another within an object and conduction of heat occurs when molecules increase in temperature.
Convection is a transfer of heat by the movement of a fluid. Convection occurs within liquids and gases between areas of different temperature.
Answer:
a) <em>8.33 x 10^-6 Pa</em>
b) <em>8.23 x 10^-11 atm</em>
c) <em>1.67 x 10^-5 Pa</em>
d) <em>1.65 x 10^-10 atm</em>
<em></em>
Explanation:
Intensity of the light 
= 2500 W/m^2
speed of light 
<u> </u>= 3 x 10^8 m/s
a) we know that the pressure for for a totally absorbing surface is given as
= 
= 2500/(3 x 10^8) = <em>8.33 x 10^-6 Pa</em>
b) 1 atm = 101325 Pa
= (8.33 x 10^-6)/101325 = <em>8.23 x 10^-11 atm</em>
c) for a totally reflecting surface
= 
= twice the value for totally absorbing
= 2 x 8.33 x 10^-6 = <em>1.67 x 10^-5 Pa</em>
d) 1 atm = 101325 Pa
= 2 x 8.23 x 10^-11 = <em>1.65 x 10^-10 atm</em>
