Physics

Question

the velocity of a car at 10:50 a.m. is 60 km per hour and at 10:52 a.m. it is 80km/h .assuming constant acceleration in the given period ,find its value​

2 Answer

  • Answer :-

    Given

    ▪️Velocity at 10:50 am = 60 km/h

    = 60 × 5/18

    = 150/9 m/s

    ▪️Velocity at 10:52 am = 80 km/h

    = 80 × 5/18

    = 200/9 m/s

    ▪️Acceleration is constant

    Now from above

    ▪️Time = 2 min = 120 sec

    Now as we have

    ▪️v = u + at

    [tex]\longrightarrow \dfrac{200}{9}= \dfrac{150}{9} + 120(a) [/tex]

    [tex]\longrightarrow \dfrac{200}{9}- \dfrac{150}{9} = 120(a) [/tex]

    [tex]\longrightarrow \dfrac{200 - 150}{9}= 120(a) [/tex]

    [tex]\longrightarrow \dfrac{50}{9}= 120(a) [/tex]

    [tex]\longrightarrow a = \dfrac{\dfrac{50}{9}}{120} [/tex]

    [tex]\longrightarrow a = \dfrac{50}{9\times120}[/tex]

    [tex]\longrightarrow a = \dfrac{5}{9\times12}[/tex]

    [tex]\longrightarrow a = \dfrac{5}{108}[/tex]

  • v = 80km/h

    u = 60 km/h

    v- u = 20 km/h

    = 20*5/18 m/s

    = 100÷18 m/s

    t = 2 minutes = 2*60 s = 120 sec

    according to first law of motion

    v = u + at

    a = (v-u)/ t

    a=100÷18÷120 m/s^2

    = 0.0462 m/s^×

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