(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The muzzle velocity of a gun found at a crime scene is tested by firing the 100 g bullet

into a block of mass 9.9 kg. The block is initially at rest on a frictional surface,

coefficient of 0.1. The bullet sticks into the block and the combination slides a total

distance of 4.5 metres along the surface. Calculate the muzzle velocity of the gun.

2. Relevant equations

This collision is inelastic.

Fy = 0 = Fn = Fg = mg(Force in y)

Ff = uFn = (.1)(9.9kg)(9.8m/s^2) = 9.703N (Friction Force)

Fx = ma = (-Ff) + (Fa)

vx = dx/t

mBvB + mLvL = v'(mB + mL) (B - bullet, L - block)

mBvB = v'(mB + mL) (vL = 0)

3. The attempt at a solution

I know the frictional force, if I could find a way to figure out the v' in the momentum equation, I could figure everything out. Now I know the displacement, if there was some way I could find the time, or even acceleration. I think I might have ideas on how to taclke the problems, but I can't get too far, I am still going to try, if anyone could help that would very well appreciated. Thank You.

I am missing a peice of the puzzle to finish the question.

1. The problem statement, all variables and given/known data

Two titanium spheres approach each other head-on with the same speed and collide

elastically. After the collision, one of the spheres, whose mass is 300 g, remains at rest.

What is the mass of the other sphere?

2. Relevant equations

Momentum Conserved

m1v1 + m2v2 = m1v1' + m2v2' (v2' = 0, v1 = v2, m1 = .3kg)

v(m1+m2) = m2v2'

m1v1^2 + m2v^2 = m2v2'^2(should I factor?)

v^2(m1 + m2) = m2v2'^2

3. The attempt at a solution

Right now I have a feeling that I should be isolating for m2 or something so I can cancel it out when I sub into another equation.

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# Homework Help: Bullet on a Block(Momentum)

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