Finding Final Velocity by Energy Techniques

AI Thread Summary
The discussion revolves around calculating the final velocity of a snowball fired from a cliff using energy conservation techniques. The initial parameters include a mass of 1.50 kg, an initial velocity of 14.0 m/s, and a height of 13.5 m. The correct approach involves using the equation for kinetic and potential energy, but the user initially made an error in calculations, leading to an incorrect final velocity. After clarification, the correct final velocity is determined to be 21.5 m/s. The conversation highlights the importance of careful calculations and checking for errors in problem-solving.
GingerBread27
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A 1.50 kg snowball is fired from a cliff 13.5 m high with an initial velocity of 14.0 m/s, directed 41.0° above the horizontal.
(a) Using energy techniques, rather than techniques of Chapter 4, find the speed of the snowball as it reaches the ground below the cliff.
ok so I used the equation k1+u1=k2=u2
plugging in numbers i did 1/2(1.50kg)(14m/s)^2+(1.50kg)(9.8m/s^2)(13.5m)=1/2(1.50kg)(vf)^2+(1.50kg)(9.8m/s)(0). Then I solve for Vf and I get a wrong answer. Now i realize this is probably wrong since I haven't incorporated the angle, but I'm not sure. Any ideas?
 
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Well. The technique is right, so you must've made some silly error in solving for Vf.
What answer did you get? It should be 21.5 m/s.
 
Yeah 21.5 is the answer, guess I must have made a mistake with the calculator :blushing: . Thank You :smile:
 
Hey GingerBread27 please check your private messages...thanks!
 
GingerBread27 check your private messages 1 more time...thanks
 

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