Answer:
Part a)

Part b)

Part c)

Explanation:
Part a)
De broglie wavelength is given as



Part b)
By principle of uncertainty we know that



Part c)
As we know that

also we know


now we have



C. The forces on an object traveling at terminal velocity are balanced.
Answer:
Please find detailed explanation of second class levers below
Explanation:
Levers are one of the classes of machine that possesses three levels namely: first class, second class and third claas. A second class lever is the level of levers in which the load (L) is in between the pivot (F) and the effort (E).
Examples of second class levers include; wheelbarrow, a bottle opener etc. In the bottle opener for example, the bottle lid (load) is in between the pivot of the opener and the hand opening it (effort).
Answer:
The change in entropy ΔS = 0.0011 kJ/(kg·K)
Explanation:
The given information are;
The mass of water at 20.0°C = 1.0 kg
The mass of water at 80.0°C = 2.0 kg
The heat content per kg of each of the mass of water is given as follows;
The heat content of the mass of water at 20.0°C = h₁ = 83.92 KJ/kg
The heat content of the mass of water at 80.0°C = h₂ = 334.949 KJ/kg
Therefore, the total heat of the the two bodies = 83.92 + 2*334.949 = 753.818 kJ/kg
The heat energy of the mixture =
1 × 4200 × (T - 20) = 2 × 4200 × (80 - T)
∴ T = 60°C
The heat content, of the water at 60° = 251.154 kJ/kg
Therefore, the heat content of water in the 3 kg of the mixture = 3 × 251.154 = 753.462
The change in entropy ΔS = ΔH/T = (753.818 - 753.462)/(60 + 273.15) = 0.0011 kJ/(kg·K).
Answer:
Efficiency = 30% = 0.3
Explanation:
The general formula for efficiency of a device is given as:
Efficiency = (Desired Output/ Input) * 100%
Here, in our case, we have a petrol engine as a device. So, we analyze it for the efficiency calculations. Here, we have:
Chemical Potential Energy = 1000 J
Kinetic Energy = 300 J
Heat and Sound Energy = 700 J
Now, we know that the desired output of a car or the purpose of a car is to provide Kinetic energy, while all other forms of energy such as heat and sound energies are produced as waste. And the chemical energy is provided to car as input, in form of fuel. Therefore,
Input = Chemical Potential Energy = 1000 J
Desired Output = Kinetic Energy = 300 J
Therefore,
Efficiency = (300 J/1000 J) * 100%
<u>Efficiency = 30% = 0.3</u>