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A block weighing 460 g slides along a frictionless track at a speed 8.1 cm/s. It then attaches to a spring-bumper with an electromagnetic device so that the block attaches to the bumper. The bumper has a mass of 131 g, and the spring has a stiffness of 1320 kg/s2 and an equilibrium length of 8.1 cm. After the spring compresses and returns to its original length, the magnet turns off and the block launches off again, conserving energy. An Aggie does not Lie, Chegg, or Steal, or tolerate those who do. (a) How fast is the block just after it attaches to the paddle? 0.063 m/s Correct: Your answer is correct. (b) What is the maximum compression of the spring before the block turns around? 0.00133 m Correct: Your answer is correct. (c) How fast is the block moving after it launches off the paddle?

Respuesta :

Answer:

a) The speed is 6.3 cm/s

b) The maximum compression of the spring is 7.137x10⁻⁴m

c) The speed is 3.373x10⁻²m/s

Explanation:

Given data:

m₁ = 460 g = 0.46 kg

m₂ = 131 g = 0.131 kg

u₁ = 8.1 cm/s = 0.081 m/s

u₂ = 0

k = 1320

a) Applying the conservation of the momentum:

[tex]m_{1} *u_{1} =v*(m_{1} +m_{2} )\\v=\frac{m_{1} *u_{1}}{m_{1} +m_{2}} =\frac{0.46*8.1}{0.46+0.131}=6.3cm/s[/tex]

b) v = 6.3 cm/s = 0.063 m/s

The change in kinetic energy is:

[tex]delta-Ek=\frac{1}{2} (m_{1} +m_{2} )v^{2} -\frac{1}{2} m_{1} u_{1} ^{2} =\frac{1}{2} (v^{2} *(m_{1} +m_{2})-m_{1} u_{1} ^{2} )\\delta-Ek=\frac{1}{2} (0.063^{2} *(0.46+0.131)-(0.46*0.081^{2} ))=-3.362x10^{-4} J[/tex]

The change of kinetic energy is equal to the work done:

[tex]-\frac{1}{2} kx^{2} =-3.362x10^{-4} \\kx^{2} =6.724x10^{-4} \\x=\sqrt{\frac{6.724x10^{-4}}{k} } =\sqrt{\frac{6.724x10^{-4}}{1320} } =7.137x10^{-4}m[/tex]

c) The conservation of energy is:

[tex]\frac{1}{2} (m_{1} +m_{2})v^{2} =\frac{1}{2} kx^{2} \\v=\sqrt{\frac{kx^{2} }{m_{1} +m_{2}} } =\sqrt{\frac{1320*(7.137x10^{-4})^{2} }{0.46+0.131} } =3.373x10^{-2} m/s[/tex]