contestada

A 70.9-kg boy and a 43.2-kg girl, both wearing skates face each other at rest on a skating rink. The boy pushes the girl, sending her eastward with a speed of 4.64 m/s. Neglecting friction, determine the subsequent velocity of the boy.

Respuesta :

Answer:

Explanation:

Given

mass of boy [tex]m_b=70.9\ kg[/tex]

mass of girl [tex]m_g=43.2\ kg[/tex]

speed of girl after push [tex]v_g=4.64\ m/s[/tex]

Suppose speed of boy after push is [tex]v_b[/tex]

initially momentum of system is zero so final momentum is also zero because momentum is conserved

[tex]P_i=P=f[/tex]

[tex]0=m_b\cdot v_b+m_g\cdot v_g[/tex]

[tex]v_b=-\frac{m_g}{m_b}\times v_g[/tex]

[tex]v_b=-\frac{43.2}{70.9}\times 4.64[/tex]  

[tex]v_b=-2.82\ m/s[/tex]

i.e. velocity of boy is 2.82 m/s towards west                

onyebuchinnaji

The final velocity of the boy is 2.83 m/s westward.

Conservation of linear momentum

The final velocity of the boy is determined by applying the principle of conservation of linear momentum as shown below;

Sum of initial momentum = Sum of final momentum

m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

70.9(0) - 43.2(0) = 70.9(v₁) + 43.2(4.64)

0 = 70.9v₁ + 200.448

-70.9v₁ = 200.448

-v₁ = 200.448/70.9

v₁ = -2.83 m/s

Thus, the final velocity of the boy is 2.83 m/s westward.

Learn more about conservation of linear momentum here: https://brainly.com/question/7538238

Otras preguntas