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Alenkinab [10]
4 years ago
6

A car travels 60 km in the first 2 hours and 68 km in the next 2 hours. What is the car’s average speed?

Physics
2 answers:
ch4aika [34]4 years ago
8 0

<u>Answer:</u> The average speed of the car is 32 km/hr

<u>Explanation:</u>

Average speed is defined as the ratio of total distance traveled to the total time taken.

To calculate the average speed of the runner, we use the equation:

\text{Average speed}=\frac{\text{Total distance traveled}}{\text{Total time taken}}

We are given:

Total distance traveled = (60 + 68) km = 128 km

Total time taken = (2 + 2) hr = 4 hr

Putting values in above equation, we get:

\text{Average speed of car}=\frac{128km}{4hr}=32km/hr

Hence, the average speed of the car is 32 km/hr

Nataly_w [17]4 years ago
5 0
Average speed = total distance/total time taken
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\eta= \frac{W}{Q_s}

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a) P_α =  exp (-ΔE / kT),  b)   P_β = 0.145 , d)  ΔE = 309.7 meV

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The expression for the number of molecules or particles in a given state in Boltzmann's expression

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Where k is the Bolztmann constant and T the absolute temperature

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Let's apply this expression to our case

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b) the Boltzmann constant

       k = 1,381 10⁻²³ J / K (1 eV / 1.6 10⁻¹⁹ J) = 8.63 10⁻⁵ eV / K

       kT = 8.63 105 300 = 2,589 10⁻² eV

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c) If the temperature approaches absolute zero, the so-called is very high, so there is no energy to reach the excited state, therefore or all the molecules go to the alpha state

d) For molecules to spend ¼ of the time in this beta there must be ¼ of molecules in this state since the decay is constant.

        P_β = ¼ = 0.25

     

       P_β = exp (- ΔE / kT)

       ΔE = -kT ln P_β

       ΔE = - 2,589 10⁻² ln 0.25

       ΔE = 0.3097 eV

       ΔE = 309.7 meV

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