A 5.00 g object moving to the right at 20.0 cm/s makes an elastic head-on collision with a 10.0 g object that is initially at rest. (a) Find the velocity of each object after the collision. -6.67 Correct: Your answer is correct. cm/s (5.00 g object) 13.33 Correct: Your answer is correct. cm/s (10.0 g object) (b) Find the fraction of the initial kinetic energy transferred to the 10.0 g object. 88.44 Correct: Your answer is correct. %

Respuesta :

Answer:

a) [tex]v_{1f}=-6.67\: cm/s[/tex]

[tex]v_{2f}=13.33\: cm/s[/tex]

b) [tex]n=88.84\: \%[/tex]  

Explanation:

a) Applying the conservation of momentum, we have:

[tex]p_{i}=p_{f}[/tex]

p(i) is the initial momentum. In our case is due to the 5 g object.

p(f) is the final momentum. Here, both objects contribute.

[tex]m_{1i}v_{1i}=m_{1f}v_{1f}+m_{2f}v_{2f}[/tex]  

Where:

  • m(1) is 5 g
  • m(1) is 10 g
  • v(1i) is the initial velocity 20 cm/s or 0.2 m/s

To find both final velocities we will need another equation, let's use the conservation of kinetic energy.

[tex]m_{1i}v_{1i}^{2}=m_{1f}v_{1f}^{2}+m_{2f}v_{2f}^{2}[/tex]  

So we have a system of equations:

[tex]5*0.2=5v_{1f}+10v_{2f}[/tex]  (1)

[tex]5*0.2^{2}=5v_{1f}^{2}+10v_{2f}^{2}[/tex] (2)

Solving this system we get:            

[tex]v_{1f}=-6.67\: cm/s[/tex]

[tex]v_{2f}=13.33\: cm/s[/tex]

b) The  fraction of the initial kinetic energy transferred is:

[tex]n=\frac{m_{2}v_{2f}^{2}}{m_{1}v_{1i}^{2}}[/tex]

[tex]n=\frac{10*13.33^{2}}{5*20^{2}}[/tex]

[tex]n=88.84\: \%[/tex]

I hope it helps you!