Answer:
The change in internal energy is zero.
(a) is correct option
Explanation:
Given that,
Work done W = -400 J
The First law of thermodynamics is law conservation of energy
Law of conservation energy is defined the total amount of energy is constant in isolated system.
The energy can not be created and destroyed but the energy can be changed from one form to other form.
The First law of thermodynamics is given by
Where,
W = work done by the system or on the system
= Total internal energy
Q = heat
In isothermal process, the temperature is constant
The energy can not be change and the internal energy is the function of temperature.
So, The internal energy will be zero .
Hence, The change in internal energy is zero.
Answer:
Explanation:
If the distance () and speed (), measured in centimeters and centimeters per hour, respectively, are directly proportional to each other, then each set of values must observe the following relationship:
(Eq. 1)
Where is the proportionality constant, measured in .
If we know that , , , , and , then the constant of proportionality for each pair is:
As , we conclude that correct equation is .
Answer:
A. Far away stars show a red shift and B. Microwave background creation is found all over the observational universe
Explanation:
Red shift in color indicates that galaxies are moving away from Earth. This is proof that the Universe is continously expanding, which also supports the big bang theory.
The Big Bang theory predicts that the early universe was a very hot place and that as it expands, the gas within it cools. Thus the universe should be filled with radiation that is literally the remnant heat left over from the Big Bang, called the “cosmic microwave background".
I hope this helps :)
Answer:
a) α = 0.338 rad / s² b) θ = 21.9 rev
Explanation:
a) To solve this exercise we will use Newton's second law for rotational movement, that is, torque
τ = I α
fr r = I α
Now we write the translational Newton equation in the radial direction
N- F = 0
N = F
The friction force equation is
fr = μ N
fr = μ F
The moment of inertia of a saying is
I = ½ m r²
Let's replace in the torque equation
(μ F) r = (½ m r²) α
α = 2 μ F / (m r)
α = 2 0.2 24 / (86 0.33)
α = 0.338 rad / s²
b) let's use the relationship of rotational kinematics
w² = w₀² - 2 α θ
0 = w₀² - 2 α θ
θ = w₀² / 2 α
Let's reduce the angular velocity
w₀ = 92 rpm (2π rad / 1 rev) (1 min / 60s) = 9.634 rad / s
θ = 9.634 2 / (2 0.338)
θ = 137.3 rad
Let's reduce radians to revolutions
θ = 137.3 rad (1 rev / 2π rad)
θ = 21.9 rev