General Thoughts: Physics (4 Viewers)

salcoo

New Member
Joined
Oct 2, 2015
Messages
11
Gender
Undisclosed
HSC
2015
Did anyone happen to get 7700 m/s for the velocity of the satellite ?
 

IamKirby

Member
Joined
Feb 13, 2014
Messages
46
Gender
Male
HSC
2015
Did anyone happen to get 7700 m/s for the velocity of the satellite ?
Yeah I read someone did but I fucked it up BECAUSE I DIDNT READ THE UNITS. Sorry just pissed at myself because it was the easiest question in the exam.


Sent from my iPhone using Tapatalk
 

Drsoccerball

Well-Known Member
Joined
May 28, 2014
Messages
3,650
Gender
Undisclosed
HSC
2015
did your line of best fit start from 0?
Yes it did because when the range is 0 the horizontal speed is 0.
Also we drew a line of best-fit for a reason, we have to use a point that lies on the line.
Also ill upload a sketch of what I did for the trolley/ cart question.
 

Drsoccerball

Well-Known Member
Joined
May 28, 2014
Messages
3,650
Gender
Undisclosed
HSC
2015
It doesn't asymptote to zero but rather to a speed since there was no friction ( Since velocity never changed without the magnet).
 

apurba

Member
Joined
Nov 29, 2013
Messages
58
Gender
Male
HSC
2015
how come velocity doesn't increase again haha this is probs stupid as but I drew an increase in velocity after it leaves the magnet because i thought the direction of eddy currents would change & so the trolley would experience a force in the opposite direction, causing its velocity to gain slightly.

where did i go wrong haha
 

apurba

Member
Joined
Nov 29, 2013
Messages
58
Gender
Male
HSC
2015
It doesn't decrease through B and C

If you measure the trolley with the A-B-C-D range you'll find both are exactly 3cm

It should start decreasing slightly before since the magnet isn't situated exactly at point B

and since the magnet will continue attracting after the front of the copper has slid through (i.e. the back of the copper bar) it should begin increasing just before D
yeah this is what i did
 

PhysicsMaths

Active Member
Joined
Dec 9, 2014
Messages
179
Gender
Male
HSC
2015
I don't understand at all how velocity will increase. Where is the energy for the increase coming from?


Sent from my iPhone using Tapatalk
Nowhere. They have violated the law of conservation of energy / momentum.
 

Drsoccerball

Well-Known Member
Joined
May 28, 2014
Messages
3,650
Gender
Undisclosed
HSC
2015
Shouldnt it have a horizontal point of inflexion somewhere, as when the copper plate is directly below the magnet, it experiences a constant flux, thus no change according to Lenz's law?
But theres still a change in flux ?
 

Drsoccerball

Well-Known Member
Joined
May 28, 2014
Messages
3,650
Gender
Undisclosed
HSC
2015
At the point where its directly under? So like the same situation of when you have something moving within a field, and when its completely immersed, has no induced current.
Lets just say the magnetic field at 0.0001 meters away from the middle is X and right under is Y. Change in flux = X-Y and thus since they're not equal there has to be a change in flux? no?
 

Users Who Are Viewing This Thread (Users: 0, Guests: 4)

Top