- #1

TheFireFox

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## Homework Statement

3. A bullet of mass m is moving horizontally with speed v

_{o}when it hits a block with mass 100m that is at rest on a horizontal frictionless table. The surface of the table is height h above the floor. After the impact the bullet and the block slide off the table and hit the floor at a distance x from the edge of the table.

Derive expressions in terms of m, h, V

_{o}, and constants.

A. The speed of the block as it leaves the table

B. Delta KE of the system during impact

C. The horizontal distance X.

If the bullet passes through:

D. Is the time to reach the floor greater, smaller or equal/ Why?

E. Is the distance x smaller, greater equal/ Why?

## Homework Equations

I'm assuming that conservation of momentum has something to do with part A; Delta KE= KE

_{f}- KEr

_{i}, and KE= (0.5)mv

^{2}for part B, General kinematics equations for Part C (I'm guessing D= V

_{i}t+0.5at

^{2}) , and I'm confused about D and E.

## The Attempt at a Solution

A. mV

_{o}=(m+100m)V

_{f}

V

_{f}=(mV

_{o}) / (m+100m) = mV

_{o}/ m(1+100) = V

_{o}/101

B. Delta KE = KE

_{f}-KE

_{i}

=0.5(1+100m)V

_{f}

^{2}- 0.5 mV

_{o}

^{2}

C. x=V

_{i}+ 0.5at

^{2}

I'd greatly appreciate any help/feedback.