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physicsluv
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Homework Statement
A(n) 9 g bullet is fired into a 396 g block
that is initially at rest at the edge of a frictionless table of height 0.9 m. The bullet remains
in the block, and after impact the block lands
2.3 m from the bottom of the table.
The acceleration of gravity is 9.8 m/s.
Homework Equations
ΔX = Vi(t) + (1/2)(a)(t^2)
m(Vf-Vi) = -m(Vf-Vi)
The Attempt at a Solution
I separated the equation into vertical and horizontal parts.
Horizontal: ΔX=2.3, a = 0 m/s/s
Vertical: ΔY= .9, a= -9.8 m/s/s, Vi = 0 m/s (because it is launched horizontally).
Using the kinematic equation ΔX = Vi(t) + (1/2)(a)(t^2) to solve for the vertical time:
t = 0.4285714286 seconds
Since the vertical time is equal to the horizontal time, I plugged this time into the same kinematic equation to solve for the horizontal Vi:
Vi = 5.366666667 m/s
Now, I know you need to use the collision equation to solve for the initial velocity in the bullet, but I do not know how to set it up...
I have this so far
9(5.366666667-vi)=-____?_____
Thank you for the help :)