Answer:
The net amount of energy change of the air in the room during a 10-min period is 120 KJ.
Explanation:
Given that
Heat loss from room (Q)= 60 KJ/min
Work supplied to the room(W) = 1.2 KW = 1.2 KJ/s
We know that 1 W = 1 J/s
Sign convention for heat and work:
1. If heat is added to the system then it is taken as positive and if heat is rejected from the system then it is taken as negative.
2. If work is done by the system then it is taken as positive and if work is done on the system then it is taken as negative.
So
Q = -60 KJ/min
In 10 min Q = -600 KJ
W = -1.2 KJ/s
We know that
1 min = 60 s
10 min = 600 s
So W = -1.2 x 600 KJ
W = -720 KJ
WE know that ,first law of thermodynamics
Q = W + ΔU
-600 = - 720 + ΔU
ΔU = 120 KJ
The net amount of energy change of the air in the room during a 10-min period is 120 KJ.
Answer:
180 x 60 inches
Width = 60 inches
Length = 180 inches
Explanation:
Given
Let L = Length
W = Width
P = Perimeter
Length = 3 * Width
L = 3W
Perimeter of Brass = 480 inches
P = 480
Perimeter is given as 2(L + W);
So, 2 (L + W) = 480
L + W = 480/2
L + W = 240
Substitute 3W for L; so,
3W + W = 240
4W = 240
W = 240/4
W = 60 inches
L = 3W
L = 3 * 60
L = 180 inches
The following scenarios are pertinent to driving conditions that one may encounter. See the following rules of driving.
<h3>What do you do when the car is forced into the guardrail?</h3>
Best response:
- I'll keep my hands on the wheel and slow down gradually.
- The reason I keep my hands on the steering wheel is to avoid losing control.
- This will allow me to slowly back away from the guard rail.
- The next phase is to gradually return to the fast lane.
- Slamming on the brakes at this moment would result in a collision with the car behind.
Scenario 2: When driving on a wet road and the car begins to slide
Best response:
- It is not advised to accelerate.
- Pumping the brakes is not recommended.
- Even lightly depressing and holding down the brake pedal is not recommended.
- The best thing to do is take one foot off the gas pedal.
- There should be no severe twists at this time.
Scenario 3: When you are in slow traffic and you hear the siren of an ambulance behind
Best response:
- The best thing to do at this moment is to go to the right side of the lane and come to a complete stop.
- This helps to keep the patient in the ambulance alive.
- It also provide a clear path for the ambulance.
- Moving to the left is NOT recommended.
- This will exacerbate the situation. If there is no place to park on the right shoulder of the road, it is preferable to stay in the lane.
Learn more about rules of driving. at;
brainly.com/question/8384066
#SPJ1
Answer:
can you please ask in English I can't understand this language
Answer:
If the heat engine operates for one hour:
a) the fuel cost at Carnot efficiency for fuel 1 is $409.09 while fuel 2 is $421.88.
b) the fuel cost at 40% of Carnot efficiency for fuel 1 is $1022.73 while fuel 2 is $1054.68.
In both cases the total cost of using fuel 1 is minor, therefore it is recommended to use this fuel over fuel 2. The final observation is that fuel 1 is cheaper.
Explanation:
The Carnot efficiency is obtained as:
Where 
is the atmospheric temperature and 
is the maximum burn temperature.
For the case (B), the efficiency we will use is:
The work done by the engine can be calculated as:
where Hv is the heat value.
If the average net power of the engine is work over time, considering a net power of 2.5MW for 1 hour (3600s), we can calculate the mass of fuel used in each case.
If we want to calculate the total fuel cost, we only have to multiply the fuel mass with the cost per kilogram.
