projectile motion (1 Viewer)

[greengirl]

hey, can anyone help me with this question? its Q1 from 2004 hsc.

Basically its says 2 balls are fired at different angles. ball Q goes twice as far as ball Q but they both reach the same max height.

which one is not true:
they both have same time of flight or
they both have the same initial velocity?

this is a multiple choice, but the other answers are ruled out.

thanks for the help

 

[passion89]

They wouldn't have the same initial velocity because initial velocity determines range.

So I'd say that one wouldn't be true.

 

[annieclassof06]

2 balls are fired at different angles. ball 2 goes twice as far as ball 1 but they both reach the same max height.

Well.. If ball 2 is travelling further at the same height its going to take longer to get there so that rules out same flight time.

So ball 2 must have been hit with abit more "thwack" (or "oompf") if it travels further. Which means the cricketer has hit it harder at a different angle giving you answer (B) they have different initial velocity

 

[annieclassof06]

You are forgetting that the horizontal and vertical components of motion are independent.

Yes yes I was... Bugger... I oughta remember that for tomorrow then..

 

[Ennaybur]

green girl where are u from?