Projectile motion question. Please help me :). I'm stuck on part c. Initial velocity means at t=0, v=? Right?
So if x = vt cos alpha, and vcos alpha= 4
Then x= 4t.. So wouldn't you just differentiate x=4t to find the velocity?
So initial velocity = 4 ? Or is this a trick question?....

Question

Projectile motion question. Please help me :). I'm stuck on part c. Initial velocity means at t=0, v=? Right? 
So if x = vt cos alpha, and vcos alpha= 4 
Then x= 4t.. So wouldn't you just differentiate x=4t to find the velocity? 
So initial velocity = 4 ? Or is this a trick question?....

butterflydreamer · Answer

Oh part c question 12 of the attachment :)

rhystic · Answer

there is no attachment....

butterflydreamer · Answer

:/. I'll try add it again 
Can you see it now?

amistre64 · Answer

how do we prove part a?  since a frisbee has different dynamics then say a ball or or a rock or an anvil.

butterflydreamer · Answer

hmm.. i used the same basic method as with a ball/rock/frisbee...

amistre64 · Answer

a flying frisbee does not fall like a rock.  the acceleration is altered by its motion of flight.

ive thrown a frisbee, and a rock ... they dont have the same trajectories.

amistre64 · Answer

in a vacuum cleaner they might ...

amistre64 · Answer

the derivative of position will give us velocity, but im not sure what math you are able to use

butterflydreamer · Answer

I guess that's true but the question doesn't really mention that?
Using the same general method, i still managed to prove part a:
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