A 12.4-g marble is dropped from rest onto the floor 1.56 m below. If the marble bounces straight upward to a height of 0.614 m, what is the magnitude of the impulse delivered to the marble by the floor

Respuesta :

Answer:

The impulse is    [tex]I= 0.1116\ kg \cdot m/s[/tex]

Explanation:

Generally Impulse which the change in momentum  is mathematically represented as

                          [tex]I = m\Delta v[/tex]

Where m is the mass  with a value 12.4g = [tex]\frac{12.4}{1000} = 12.4*10^{-3}kg[/tex]

           [tex]\Delta v[/tex] is the change in velocity which is mathematically represented as

                  [tex]\Delta v = v_2 -v_1[/tex]

Where [tex]v_1[/tex] s the velocity of the marble drooping and [tex]v_2[/tex] is the velocity of the marble bouncing back

setting up in a coordinate y-axis would show that [tex]v_1[/tex] is moving in the negative y-direction so the  value would be [tex]v_1 = -v_1[/tex] and  [tex]v_2[/tex] is moving in the positive  y-direction so the  value would be [tex]v_2 = +v_2[/tex]

So the formula for [tex]\Delta v[/tex] would be

           [tex]\Delta v = v_2 -( -v_1)[/tex]

           [tex]\Delta v = v_1 +v_2[/tex]

General v i mathematically represented as

                  [tex]v = \sqrt{2gh}[/tex]

 Substituting this into the formula for [tex]\Delta v[/tex]

                 [tex]\Delta v = \sqrt{2gh_2} + \sqrt{2gh_1}[/tex]

Now substituting values as given in the question

                 [tex]\Delta v = \sqrt{2 * 9.8 *0.614 } + \sqrt{2 * 9.8 *1.56 }[/tex]

                       [tex]= 8.9986 m/s[/tex]

The impulse is

                 [tex]I = 12.4*10^{-3} * 8.9986[/tex]

                   [tex]I= 0.1116\ kg \cdot m/s[/tex]