Projectile Motion (Initial Velocity)

[Milkster18]

one revolution = 2*pi radians

31.5 / 2*pi = just over 5 revolutions :)

but i had to find 2*pi first then use that answer to divided into 31.5 rads.. otherwise the answer will be completely different for some reason.

As for average angular speed:

20 / 2 = 10 rpm?

 

[Doc Al]

one revolution = 2*pi radians

31.5 / 2*pi = just over 5 revolutions :)

Good.

but i had to find 2*pi first then use that answer to divided into 31.5 rads.. otherwise the answer will be completely different for some reason.

Not sure what you mean.

As for average angular speed:

20 / 2 = 10 rpm?

No. It goes from 20 rpm to 40 rpm, so what would the average be? (It can't be 10 rpm!)

 

[Milkster18]

Ah

W1 + W2 / 2

20 + 40 / 2 = 30 rpm

So now i have average how does this make things easier?

Im from the UK by the way so i think some units / symbols are different to US if your from there.

Thanks for the help again. :)

 

[Doc Al]

Ah

W1 + W2 / 2

20 + 40 / 2 = 30 rpm

Good.

So now i have average how does this make things easier?

Use the same formula as before: Distance = ave speed X time
Here "distance" is replaced by angle/revolutions.

Hint: How many minutes is 10 seconds?