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    Keymaster
    July 6, 2018 at 12:28 pm
    Post count: 1622
    #13893
    Blood Alcohol Content – BAC

    $$BA{C_{Male}} = \frac{{10N – 7.5H}}{{6.8M}}$$

    N = number of drinks H = hours drinking M = Mass in kg

    $$BA{C_{Female}} = \frac{{(10N – 7.5H)}}{{5.5M}}$$

    Limitations on estimating BAC include food, medication interactions, errors in estimating the number of drinks and time period

    $$t= \frac{BAC}{0.015}$$

    time taken to reach a zero BAC

    1 standard drink = 10 g alcohol

    $$N = 0.789VA$$

    N = number of standard drinks
    V = volume of drink in L
    A = alcohol percent content

    Admin
    Keymaster
    January 1, 2021 at 12:41 pm
    Post count: 1622
    #18933

    Find the value of H in the formula $$BA{C_{Male}} = \frac{{10N – 7.5H}}{{6.8M}}$$ if:

    a. BACMale = 0.066, M = 60 and N = 5, correct to the nearest minute.

    b. BACMale = 0.050, M = 79 and N = 7, correct to the nearest minute.

    a. $$0.066=\frac{10\times5-7.5H}{6.8\times60}$$

    $$0.066=\frac{50-7.5H}{408}$$  multiply both sides by 408

    26.928 = 50 – 7.5H    subtract 50 from both sides

    -23.072 = -7.5H   divide both sides by -7.5

    H = 3.076   (change to hours and minutes)

    H = 3 hours 5 minutes  

    b. $$0.05=\frac{10\times7-7.5H}{6.8\times79}$$

    $$0.05=\frac{70-7.5H}{537.2}$$  multiply both sides by 537.2

    26.86 = 70 – 7.5H    subtract 70 from both sides

    -43.14 = -7.5H   divide both sides by -7.5

    H = 5.752   (change to hours and minutes)

    H = 5 hours 45 minutes

    Admin
    Keymaster
    January 1, 2021 at 12:43 pm
    Post count: 1622
    #18934
    Calculate the BAC for Joanne if she weighs 50kg and has 4 standard drinks in 2 hours.
    $$BA{C_{Female}} = \frac{{(10\times4 – 7.5\times2)}}{{5.5\times50}}$$ Use the BAC formula for a female $$BA{C_{Female}} = \frac{{(10N – 7.5H)}}{{5.5M}}$$, substituting N = 4, H = 2 and M = 50
    = 0.090909 calculate
    = 0.09 round correct to 2 decimal places
    Admin
    Keymaster
    January 1, 2021 at 12:44 pm
    Post count: 1622
    #18935
    Find the value of H, correct to the nearest minute, in the formula $$BA{C_{Male}} = \frac{{10N – 7.5H}}{{6.8M}}$$ if:
    a. $$BA{C_{Male}} =0.066$$, M = 60 and N = 5
    b. $$BA{C_{Male}} =0.050$$, M = 70 and N = 7
    a. $$0.066=\frac{10\times5-7.5H}{6.8\times60}$$ substitute the values into the equation 
    $$0.066=\frac{50-7.5H}{408}$$ multiply both sides by 408
    26.928 = 50 – 7.5H subtract 50 from both sides
    -23.072 = -7.5H divide both sides by -7.5
    H = 3.076 change to hours and minutes, using the degrees and minutes button
    H = 3 hours 5 minutes  
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