The spring of a spring gun has force constant k = 400 N/m and negligible mass. The spring is compressed 6.00 cm and a ball with mass 0.0300 kg is placed in the horizontal barrel against the compressed spring. The spring is then released, and the ball is propelled out the barrel of the gun. The barrel is 6.00 cm long, so the ball leaves the barrel at the same point that it loses contact with the spring. The gun is held so the barrel is horizontal.
1) Calculate the speed of the ball as it leaves the barrel if a constant resisting force of 6.00 N acts on the ball as it moves along the barrel.
2) For the situation in part (1), at what position along the barrel does the ball have the greatest speed? (In this case, the maximum speed does not occur at the end of the barrel.)
KE = 1/2mv^2
The Attempt at a Solution
I solved the first part already and I have 4.90m/s but I'm stuck on the second one. When does it have the greatest speed anyway? I'm thinking that's when the KE is the greatest and positive? Is this correct?
...That's probably wrong because I tried it and had the wrong answer.