Anonymous
Anonymous asked in Science & MathematicsPhysics · 8 months ago

Shawn and his bike have a total mass of 52.8 kg. Shawn rides his bike 0.91 km in 13.1 min at a constant velocity.?

Shawn and his bike have a total mass of

52.8 kg. Shawn rides his bike 0.91 km in

13.1 min at a constant velocity.

The acceleration of gravity is 9.8 m/s

2

.

What is Shawn’s kinetic energy?

5 Answers

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  • MyRank
    Lv 6
    8 months ago

    Given,

    Mass (m) = 52.8kg 

    Distance (d) = 0.91km = 0.91 x 10³m 

    Time (t) = 13.1mins = 786sec 

    Acceleration due to gravity (g) = 9.81m/sec² 

    Kinetic Energy (K.E) = ? 

    We know that:- 

    Kinetic Energy (K.E) = ½mv² = ½ x 52.8kg x [(0.91 x 10³m) / 786sec]²  

    = ½ x 52.8 x (1.158)² 

    = 35.4J 

    ∴ Kinetic Energy (K.E) = 35.4J 

  • 8 months ago

    d = distance that Shawn has ridden = 0.91 km = 910 m

    t = time that Shawn has ridden = 13.1 min = 786 s

    v = velocity = d / t = 1.157760814 m/s

    m = combined mass of Shawn and his bike = 52.8 kg

    KE = kinetic energy to be determined

    KE = 0.5mv²

    KE = 0.5(52.8 kg)(1.16 m/s)²

    KE = 35.38682672 J ≈ 35.4 J

  • 8 months ago

    This is a conversions problem.  We know that Ek = 1/2 m v^2

    but to get the energy in known units the velocity MUST be in metres per second.  v = s/t   s = 0.91 km -> 910 m.  t= 13.1 min -> 13.1*60s  -> v= 910/(13.1*60)

    Shawn's bike is a superlightweight bike of 8.2 kg giving HIS mass as 44.6 kg

     so Ek Shawn= 1/2 * 44.6 *(910/(13.1*60) )^2  = 29.9 J

  • Anonymous
    8 months ago

    the answer was 35.4 J, found by whome

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  • Anonymous
    8 months ago

    speed = distance / time

    convert km/min to m/sec

      

    KE = 1/2 * mass * speed^2

    < what do you mean?? >

    You need to start paying attention in class or you'll be redoing it.  Your choice.

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