Explanation:
- A thermometer does measure the temperature of a body and not the heat. It is known that temperature is a measure of average kinetic energy.
Therefore, the statement a thermometer measures the average kinetic energy of a substance is correct.
- Heat is a form of energy as it can make a colder substance become hot and it moves from one place to another. Thus, the statement heat is a form of energy is correct.
- Also, heat flows from hotter substance to colder substance. Hence, the statement heat flows from a colder substance to a hotter substance is correct.
- Convection is a property of fluids or gases which makes less denser (hot) material to rise and more denser (colder) material to sink.
Therefore, the statement convection occurs only in liquids and gases is correct.
- All substances radiate heat is an incorrect statement. For example, a thermos bottle does not radiate heat.
- Temperature of our body is about 98.4 degree celsius and hence we can conclude that the statement our body temperature is always equal to the temperature around us is incorrect.
Hi there!
a.
We can use the initial conditions to solve for w₀.
It is given that:
We are given that at t = 0, ω = 3.7 rad/sec. We can plug this into the equation:
Now, we can solve for sigma using the other given condition:
b.
The angular acceleration is the DERIVATIVE of the angular velocity function, so:
c.
The angular displacement is the INTEGRAL of the angular velocity function.
Convert this to rev:
d.
We can begin by solving for the time necessary for the angular speed to reach 0 rad/sec.
Evaluate the improper integral:
Convert to rev:
I’m almost 100 percent sure it’s the first one
Answer:
V = I * R
R = 2 / 3.5 = .571 ohms maximum resistance of wire
R = ρ L / A where R is proportional to L and inversely proportional to A
A = ρ L / R minimum area of wire
ρ = 1 / μ = 1.67E-8 ohm-m resistivity inverse of conductivity
A = 1.67E-8 ohm-m * 225 m / .571 ohm = 6.68E-6 m^2
A = 6.68 mm^2 since 1 mm^2 = 10-6 m^2 or 1 mm = 10-3 m
A = Π r^2 = 6.68 mm^2
r = (6.68 / 3.14)^1/2 mm = 2.13 mm radius of wire
d = 2 * r = 4.26 mm
Answer:
B. 81
Explanation:
When you multiply two numbers, round the answer to the least number of significant figures available. 67.6 has three significant figures, and 1.2 has two significant figures. So we round to two significant figures.
