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~christina~
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Homework Statement
The spring constant of a experimental spring gun is 350N/m. The spring is compresed a distance of 80cm from it's equillibrium position and a 1.5kg musket ball is placed in the barrel against the compressed spring. When the gun is fired the spring extends the length of the barrel, propelling the ball out of the barrel. The barrel makes a angle with 30 deg witht he horizontal, and the coefficient of kinetic friction between the ball and the barrel is 0.57. Assume the spring is massless.
a) Draw a free body diagram for the musket ball after the ball has been fired and the ball is 10cm below the spring's equillibrium position.
b) What is the acceleration of the ball at this position?
c) Use the work-energy theorem to determine the speed of the musket ball as it leaves the end of the barrel.
d) What maximum height does the ball reach after it leaves the barrel?
e) draw a free-body diargram for the musket ball at it's maximum height
http://img209.imageshack.us/img209/605/balljd0.th.jpg
Homework Equations
K+ Ug + Us = K + Ug + Us
The Attempt at a Solution
a) free body diagram of ball at position 10cm below the equillibrium point after it has been fired.
I really don't know but I assume that 10 cm below the equillibrium of the spring that the only force on the ball is the mass and the force of gravity on the ball. (see picture that I drew)
b)What is acceleration of ball at this position?
Would it just be the acceleration due to gravity? (9.81m/s^2)
c) Use the Work-energy to determine the speed of the musket ball as it leaves the end of the barrel?
Kf+ Ug + Us = K + Ug + Us- fkd
I know I would have to use this but I also have to include friction but I'm not sure how...(it would have to be angled)
[tex]1/2 mv^2 + mgysin \theta = 1/2mv^2 + mgysin theta + 1/2kx^2- \mu_kmg [/tex]
I need help on the equation set up.
HELP!
Thanks
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