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A 29.6 kg dog is running northward at 2.90 m/s , while a 7.70 kg cat is running eastward at 3.76 m/s . Their 76.7 kg owner has the same momentum as the two pets taken together. Find the direction and magnitude of the owner's velocity.

Respuesta :

Answer

given,

mass of the dog = 29.6 Kg

speed in northward = 2.90 m/s

mass of cat = 7.70 Kg

speed of the cat in eastward = 3.76 m/s

Mass of owner = 76.7 Kg

Momentum of dog

P_y = m₁ x u₁

P_y = 29.6 x 2.9

P_y = 85.84 Kg.m/s

P_x = m₂ x u₂

P_x = 7.7 x 3.76

P_x =28.952 Kg.m/s

magnitude of momentum

[tex]P = \sqrt{P_x^2+P_y^2}[/tex]

[tex]P = \sqrt{28.952^2+85.84^2}[/tex]

P = 90.59 Kg.m/s

[tex]\theta = tan^{-1}(\dfrac{P_y}{P_x})[/tex]

[tex]\theta =tan^{-1}(\dfrac{85.84}{28.952})[/tex]

[tex]\theta =71.36^0[/tex]

Answer:

u= 1.17 m/s

θ = 71.21 °

Explanation:

Given that

m₁=29.6 kg ,u₁=2.9 j m/s

m₂ = 7.7 kg  ,u₂=3.76 i m/s

m= 76.7 kg

The speed of the mass 76.7 kg = u m/s

The linear momentum

m₁ u₁+m₂u₂ = m u

29.6 x 2.9 j + 7.7 x 3.76 i = 76.7 u

76.7 u = 28.95 i +85.84 j

u =0.377 i +1.11 j

The magnitude of the velocity u

[tex]u=\sqrt{0.377^2+1.11^2}\ m/s[/tex]

u= 1.17 m/s

The direction θ  ( angle from eastward direction)

[tex]tan \theta= \dfrac{1.11}{0.377}[/tex]

θ = 71.21 °

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