HSC 2003 Q16) help please... (1 Viewer)

[FcUk]

Hey guys i dont know how to do Q16)a) and b) i know it should be easy but i just dont know how to read off a graph and do graphs for motion... Thanking in advance

Cheers

Daniel

http://www.boardofstudies.nsw.edu.au/hsc_exams/hsc2003exams/index4.html#p

theres the link to the paper

 

[helper]

Graph of distance versus time.
Slope = velocity

b)
range=initial velocity * time (acceleration=o in x direction)
So straight line relationship, through 0,0
Time stays the same.
Label on your graph, 1.85 m/s and 0.6 m (from graph and question)


So for any graph remember

For a Graph there are three main significant parts for physics:
1. The Slope
2. The Area under the graph
3. The intercept

When you graph something it is important to determine what these three things mean.

1. The slope is determined by looking at the equation.

2. The area is determined by looking at the product of the two axis.
Eg A graph of Force versus Time.
Product = Ft
Area = Ft = Impulse

3. The intercept, determined by looking at the equation. It can be significant if there is an intercept in an equation or if there isn't may represent a systematic error in your measurements.
Eg. A graph of velocity versus time
y=mx+b
v=mt+b
Compare to v=u+at
Intercept = initial velocity
Slope = acceleration

 

[Jase]

Yeh that one was a bitch.

Okay.. well the first one is pretty simple.. the velocity is just the gradient of the graph.

Second one, use the golden rule: Indepedent on X-axis, depedent variable on Y.
The depedent variable is the range. so plot that Y. And the velocity on X... you'd probably want to begin by pointing out the point (1.85 , 0.6) since you know that. Then just join a straight line from there to the origin since the relationship is linear. You know it's linear because of horizontal equation of motion. x = vt

EDIT: woops, but yeh. Helper's talking gold there. Just don't forget the correct labelling of axes.

 

[FcUk]

cheers guys both of u helped out

 

[Premus]

so what would be the answer for part c)
at first i thought it would be the same range(as horizontal velocity is not affected by g) ....but i know that g would affect the vertical velocity.....im confused!

Thanks

 

[helper]

Your on the right track.
What would happen to g?
Will this make the time shorter or longer?
What effect will this have on the range?

 

[Premus]

i would THINK that a lower value of g would mean that time would be longer...
and hence a longer range!
right?

 

[helper]

Thats right.
Remember to use equations to help explain.

 

[Premus]

yeaps x = vt

Thanks a lot!

 

[Shifty]

for question 16a).....dont you use v=d/t
therfore v = 1.5/0.512
= 2.9m/s???

 

[Premus]

no the velocity is the gradient of the graph
x = v t