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Sri asked in Science & MathematicsPhysics · 4 months ago

A hockey puck of mass 0.16 kg, sliding on a nearly frictionless surface of ice with a velocity of 2,0 m/s[E]...?

A hockey puck of mass 0.16 kg, sliding on a nearly frictionless surface of ice with a velocity of 2,0 m/s[E], strikes a second puck at rest with a mass of 0.17kg. The first puck has a velocity of 1.5 m/s [N 31 E] after the collision. Determine the velocity of the second puck after the collision.

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  • Ash
    Lv 7
    4 months ago
    Favorite Answer

    Momentum is conserved in elastic collision

    Let velocity in East and North direction be positive, while West and South direction be negative

    Conservation of momentum in East-West direction

    m₁ux₁ + m₂ux₂ = m₁vx₁ + m₂vx ₂

    (0.16 kg)(2.0 m/s) + (0.17 kg)(0) = (0.16 kg)(1.5sin31 m/s) + (0.17 kg)(vx ₂) 

    0.32 = 0.24sin31 + 0.17 vx ₂

    vx ₂ = (0.32 - 0.24sin31)/0.17

    vx ₂ = 1.16 m/s

    Conservation of momentum in North-South direction

    m₁uy₁ + m₂uy₂ = m₁vy₁ + m₂vy ₂

    (0.16 kg)(0) + (0.17 kg)(0) = (0.16 kg)(1.5cos31 m/s) + (0.17 kg)(vy ₂) 

    0 = 0.24cos31 + 0.17 vy ₂

    vy ₂ = (- 0.24cos31)/0.17

    vy ₂ = -1.2 m/s

    Resultant velocity = √[(1.16)² + (-1.2)²] = 1.67 m/s

    angle θ = arctan(-1.2/1.16) = -46°

    This represents E 46 S 

    The second puck moves, after collision, at 1.67 m/s at [E 46 S]

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