Answer:
a. -4.166 J/K
b. 8.37 J/K
c. 4.21 J/K
d. entropy always increases.
Explanation:
Given :
Temperature at hot reservoir , 
= 720 K
Temperature at cold reservoir , 
= 358 K
Transfer of heat, dQ = 3.00 kJ = 3000 J
(a). In the hot reservoir, the change of entropy is given by:
(the negative sign shows the loss of heat)
= -4.166 J/K
(b) In the cold reservoir, the change of entropy is given by:
= 8.37 J/K
(c). The entropy change in the universe is given by:
= -4.16+8.37
= 4.21 J/K
(d). According to the concept of entropy, the entropy of the universe is always increasing and never decreasing for an irreversible process. If the entropy of universe decreases, it violates the laws of thermodynamics. Hence, in part (c), the result have to be positive.
It says that the force of a spring is always opposite to the direction in which you stretch it or compress it. (the direction of 'x')
In other words, a spring that's disturbed always tries to put itself back to it's normal length, where x would be zero.
Answer:
The correct answer is option 'c': Smaller stone rebounds while as larger stone remains stationary.
Explanation:
Let the velocity and the mass of the smaller stone be 'm' and 'v' respectively
and the mass of big rock be 'M'
Initial momentum of the system equals
Now let after the collision the small stone move with a velocity v' and the big roch move with a velocity V'
Thus the final momentum of the system is
Equating initial and the final momenta we get
Now since the surface is frictionless thus the energy is also conserved thus
Similarly the final energy becomes
\
Equating initial and final energies we get
Solving i and ii we get
Using this in equation i we get
Thus putting v = -v' in equation i we get V' = 0
This implies Smaller stone rebounds while as larger stone remains stationary.
The time elapsed when the vehicles are closest to each other is 20 min.
The given parameters:
- Speed of the truck, u = 80 km/h
- Distance, d = 32 km
- Speed of the car, v = 50 km/h
<h3>Principles of relative speed</h3>
The time elapsed when the cars are close to each other is calculated by applying the principles of relative speed.
Thus, the time elapsed when the vehicles are closest to each other is 20 min.
Learn more about relative velocity here: brainly.com/question/24430414
Answer:
20 J/g
Explanation:
In this question, we are required to determine the latent heat of vaporization
- To answer the question, we need to ask ourselves the questions:
What is latent heat of vaporization?
- It is the amount of heat required to change a substance from its liquid state to gaseous state without change in temperature.
- It is the amount of heat absorbed by a substance as it boils.
How do we calculate the latent heat of vaporization?
- Latent heat is calculated by dividing the amount of heat absorbed by the mass of the substance.
In this case;
- Mass of the substance = 20 g
- Heat absorbed as the substance boils is 400 J (1000 J - 600 J)
Thus,
Latent heat of vaporization = Quantity of Heat ÷ Mass
= 400 Joules ÷ 20 g
= 20 J/g
Thus, the latent heat of vaporization is 20 J/g
