A pickup truck starts from rest and maintains a constant acceleration a0. After a time t0, the truck is moving with speed 25 m/s at a distan

Question

A pickup truck starts from rest and maintains a constant acceleration a0. After a time t0, the truck is moving with speed 25 m/s at a distance of 120 m from its starting point. When the truck has travelled a distance of 60 m from its starting point, its speed is v1 m/s.
Which of the following statements concerning v1 is true?
a. v1< 12.5m/s
b. v1= 12.5m/s
c. v1 >12.5m/s

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Thái Dương 4 years 2021-08-15T22:50:25+00:00 1 Answers 50 views 0

Answers ( )

  1. thienthanh
    0
    2021-08-15T22:52:24+00:00
    Reply

    Answer:

    the correct answer is c     v₁> 12.5 m / s

    Explanation:

    This is a one-dimensional kinematics exercise, let’s start by finding the link to get up to speed.

                v² = v₀² + 2 a₁ x

    as part of rest v₀ = 0

               a₁ = v² / 2x

               a₁ = 25² / (2 120)

               a₁ = 2.6 m / s²

    now we can find the velocity for the distance x₂ = 60 m

               v₁² = 0 + 2 a1 x₂

               v₁ = Ra (2 2,6 60)

               v₁ = 17.7 m / s

    these the speed at 60 m

    we see that the correct answer is c     v₁> 12.5 m / s

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