Question

For the first problem (4), did I solve it correctly?

(Assuming no friction, what is the 115 kg skier's speed at point Bat the bottom of the hill? A spring cannon with a 6g ball is pointed straight up, as shown The spring has a constant k of 100 N/M and is compressed 5 cm.What is the balls speed lust as it leaves the cannon (point A)? Note: Ignore initial 5 cm rise and air drag. Careful with units.b) What is the ball's speed at its maximum height (point C)

Answer 1

Yes since there are no other energy losses energy is conserved and what you did is absolutely right

Answer 2

Since there is no friction and hence there will be no energy loss as heat due to friction hence energy can be conserved in this case

mgh=mv²/2 ,So v²=2gh = 2*9.8*25

Hence V=22.136 m/s.

So what you did is perfectly correct.