Am I stupid... or the book? (1 Viewer)

[Brad]

In the answers to a projectile question.... a book im using says that for vertical velocity v_y = Vcos@


I am sure it should be sin..... im right arent i??

Im sure of it.... stupid book...

 

[dingding]

yeah your right

 

[Brad]

Thank you.... i was sure i was but i wanted to make sure... thanks

 

[countdown]

For final velocity in a projectile:
Vy=usin@-gt so yea its da use of sin not cos for y
so ehehe...da books wrong Not u~ shows how accurate they r ai

 

[helper]

As long as your measuring to the horizontal. Some questions don't

 

[jang]

ur stupid



hmm i just felt like saying that.

neways, yeh thats some random stuff. use the formula sheet. must we know how to use trig in the hsc? wat bout those doing general maths that have found phys interesting..

 

[mojako]

As long as your measuring to the horizontal. Some questions don't

yea it depends on what the @ is.

vertical
  |
  |\
  |b\
  |  \
  |   \
  |___a\ horizontal

if @=a then it's sin@
if @=b then a=90-b and it's sin(a) = cos@
because by the magical trigonometry, sin(90-x)=cos(x)

 

[gordo]

lol yeh of course
it depends if theta is to the horizontal or the verticle