a) Why do athletes in jumping or throwing disciplines use an approaching run as part of their acceleration?

Question

b) Neglecting air resistance and aerodynamics, what would be the best angle of release in discus throwing?

My ans:
a) To increase horizontal velocity? Since acceleration is proportional to velocty (Using common sense i would say to increase momentum etc, but we haven't covered momentum yet)
b) I have no idea =( (I just feel as if it should be less than 90degrees may be 45degrees - again this is just guessing)

Thanks

Answer 1

a)This is probably simpler.. The approaching run is used as a medium to store kinetic energy or you can also say force (F=ma), then the force/energy stored is transfered as the kinetic energy as you jump or throwing discus.

b)For this, i would say it's 30 degrees because you will have more horizontal force/energy than if you throw on 45 degrees (remember that sin 60 degrees is more than sin 45).