A fast humvee drove from desert a to desert b for the first 12 hours it travelled at an average speed of 185km/h for the next 13 hours it tr

Question

A fast humvee drove from desert a to desert b for the first 12 hours it travelled at an average speed of 185km/h for the next 13 hours it travelled at an average speed of 160km/h what was the average speed of the whole journey

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MichaelMet 3 years 2021-07-20T20:26:09+00:00 1 Answers 27 views 0

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  1. thanhcong
    0
    2021-07-20T20:28:07+00:00
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    Answer:

    The average speed of the whole journey is, v = 172 km/h

    Explanation:

    It is given that, a fast humvee drove from desert a to desert b. The scenario is as follows :

    For the first 12 hours, it traveled at an average speed of 185 km/h. Let d₁ is distance. So,

    d_1=v_1\times t_1\\\\d_1=185\ km/h\times 12\ h\\\\d_1=2220\ km

    For the next 13 hours, it traveled at an average speed of 160 km/h. Let d₂ is the distance. So,

    d_2=v_2\times t_2\\\\d_2=160\ km/h\times 13\ h\\\\d_2=2080\ km

    Average speed = total distance/time taken

    So,

    v=\dfrac{d_1+d_2}{t_1+t_2}\\\\v=\dfrac{2220+2080}{12+13}\\\\v=172\ km/h

    Therefore, the average speed of the whole journey is 172 km/h.

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