A 10.0-g bullet is fired into, and embeds itself in, a 1.95-kg block attached to a spring with a force constant of 16.6 N/m and whose mass is negligible. How far is the spring compressed if the bullet has a speed of 300 m/s just before it strikes the block and the block slides on a frictionless surface? Note: You must use conservation of momentum in this problem because of the inelastic collision between the bullet and block.

Respuesta :

Answer:

Distance the spring is compressed, x = 0.52 m  

Explanation:

Given :

Mass of the bullet, m = 10 g = 0.01 kg

Mass of the block, M = 1.95 kg

spring force constant, k = 16.6 N/m

Distance the spring is compressed =x

Speed of the bullet, v = 300 m/s

Speed of the block = V

Therefore we know that according to the law of conservation of momentum,

m.v = ( m+M )V

or [tex]V = \frac{m\times v}{m+M}[/tex]

   [tex]V = \frac{0.01\times 300}{0.01+1.95}[/tex]

              = 1.53 m/s

Now according to the law of conservation of momentum,

[tex]\frac{1}{2}\times M\times V^{2} =\frac{1}{2}\times k\times x^{2}[/tex]

[tex]x = \sqrt{\frac{\left ( M+m \right ).V^{2}}{k}}[/tex]

[tex]x = \sqrt{\frac{\left ( M+m \right )}{k}}\times V[/tex]

[tex]x = \sqrt{\frac{\left ( 1.95+0.01 \right )}{16.6}}\times 1.53[/tex]

[tex]x = 0.52[/tex] m

Thus, distance the spring is compressed, x = 0.52 m