Lizz preguntado en Science & MathematicsPhysics · hace 1 mes

Need help in physics, can anyone explain these two problems? ?

1. The figure below shows a roller coaster cart and a track. The cart is 250 kg and it starts the motion from rest at A. What is the speed of the cart at point B? 

a) 98 m/s

b) 196 m/s

c) 14 m/s

d) 10 m/s

a) What is the speed of the cart at point C? 

a) 98 m/s

b) 196 m/s

c) 14 m/s

d) 10 m/s

Attachment image

2 respuestas

Relevancia
  • hace 1 mes
    Respuesta preferida

    (A) By the law of energy conservation:

    =>KE(B) + PE(B) = KE(A) + PE(A)

    =>KE(B) - KE(A) = PE(A) - PE(B)

    =>1/2mv^2 - 0 = mghA - mghB

    =>1/2mv^2 = mg(hA -hB)

    =>1/2mv^2 = mg∆h

    =>v = √2g∆h

    =>v = √[2 x 9.81 x 5]

    =>v = 9.90 m/s ≈ 10 m/s

    =>(d)

    (B) =>v = √2g∆h

    =>v = √[2 x 9.81 x 10]

    =>v = 14 m/s

    =>(c)

  • oubaas
    Lv 7
    hace 1 mes

    1. The figure below shows a roller coaster cart and a track. The cart is 250 kg and it starts the motion from rest at A.

    1.1 What is the speed Vb of the cart at point B?

    Vb = √ 2*g(ha-hb) = √ 2*10*5 = √ 100 = 10 m/sec , no matter the mass m

    1.2  What is the speed Vc of the cart at point C?

    Vc = √ 2*g(ha-0) = √ 2*10*10= √ 200 = 14 m/sec , no matter the mass m 

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