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For lunch you and your friends decide to stop at the nearest deli and have a sandwich made fresh for you with 0.100 kg of turkey. The slices of turkey are weighed on a plate of mass 0.400 kg placed atop a vertical spring of negligible mass and force constant of 200 N/m . The slices of turkey are dropped on the plate all at the same time from a height of 0.250 m . They make a totally inelastic collision with the plate and set the scale into vertical simple harmonic motion (SHM). You may assume that the collision time is extremely small.a. What is the amplitude of oscillation A of the scale after the slices of ham land on the plate?b. What is the period of oscillation T of the scale?

Respuesta :

Answer:

a)   A = 0.0221 m, b) T = 0.314 s

Explanation:

For this exercise we must separate the process into two parts, one when the body falls and another when it hits the tray

Let's look for the speed with which it reaches the tray, using energy conservation

Initial. Highest point

        Em₀ = U = m g h

Final. Tray Point

        [tex]Em_{f}[/tex] = K = ½ m v²

        Em₀ = Em_{f}

        m g h = ½ m v²

        v = √2gh

Now let's apply moment conservation

Initial. Just before the crash

          p₀ = m v

Final. After the crash

         p_{f} = (m + M) v_{f}

         p₀ = p_{f}

         m v = (m + M) v_{f}  

         v_{f}  = m / (m + M) √2gh

This is the turkey + plate system speed, which is the one that will oscillate

b) The angular velocity of the oscillation is

           w = √ k / m

The angular velocity is related to the frequency and period

         w = 2πf = 2π / T

          T = 2π √m / k

          T = 2π √ ((0.100 + 0.400) / 200)

          T = 0.314 s

a) To find the amplitude let's use the equation that describes the oscillatory motion

            y = A cos (wt + fi)

Speed ​​is

           v = dy / dt = - A w sin (wt + fi)

At the initial point the turkey + plate system has a maximum speed, in the previous equation the speed is maximum when cos (wt + fi) = ±1

               v = v_{f}  = A w

               m / (m + M) √ 2gh = A w

               A = m / (m + M) √2gh    1 / w

               w = 2π / T

Let's calculate

              A = 0.100 / (0.100 + 0.400) √(2 9.8 0.250)   0.314/2π

            A = 0.2   2.2136   0.049975

            A = 0.0221 m