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Question- projectile motion?

abitpissy

Why use V=S/t if it's asking for horizontal velocity. Shouldn't you use x=Ut?

Reply 1

Joinedup

Original post by Questioness

Why use V=S/t if it's asking for horizontal velocity. Shouldn't you use x=Ut?

both are just different ways of stating the relationship between velocity, length and time... you can get from one to the other with a little algebra.

Reply 2

samb1234

Original post by Questioness

Why use V=S/t if it's asking for horizontal velocity. Shouldn't you use x=Ut?

Theyre exactly the same thing

Reply 3

swellow5

Original post by Questioness

Why use V=S/t if it's asking for horizontal velocity. Shouldn't you use x=Ut?

X = ut is the same thing as S = vt.
It's derived from the equation s = ut +1/2at^2.Because we are talking about the horizontal velocity we know that v = u. The ball has reached a constant velocity so it's acceleration is 0.
Substitute this in : S = vt + 1/2(0*t^2).
End result S = vt

Reply 4

samb1234

Original post by swellow5

Incredibly overcomplicated. V=s/t. V is constant horizontally so u=x/t, where x is horizontal displacement

Reply 5

swellow5

Original post by samb1234

Incredibly overcomplicated. V=s/t. V is constant horizontally so u=x/t, where x is horizontal displacement

Yeah I know, this is my first post though so I thought I should explain it in detail. Next time will keep it short buddy :smile:

Reply 6

samb1234

Original post by swellow5

Yeah I know, this is my first post though so I thought I should explain it in detail. Next time will keep it short buddy :smile:

Lol im not having a go at you, just thought it might be useful to the op to realose that there is literally no difference between the two formualas. There is no need to do any algebra because the formulas are literalky the same thing