Login

Search the forums now!

Welcome, Guest. Please login or register.

February 22, 2026, 01:16:13 am
Pages: [1] 2 3 4   Go Down

Author Topic: [Challenge] - Evaever's Physics questions  (Read 4636 times)  Share 

0 Members and 1 Guest are viewing this topic.

evaever

  • Victorian
  • Trendsetter
  • **
  • Posts: 106
  • Respect: +1
[Challenge] - Evaever's Physics questions
« on: April 17, 2011, 03:58:37 pm »
0
a 2-m long heavy non-extendable rope of uniform crossection and density lies on a frictionless horizontal surface. forces of 20 N and 15 N are applied at the ends of the rope. find the tension in the rope at 0.4 m from the 20 N end.
Logged

evaever

  • Victorian
  • Trendsetter
  • **
  • Posts: 106
  • Respect: +1
Re: [Challenge] - Evaever's Physics questions
« Reply #1 on: April 17, 2011, 04:18:21 pm »
0
a 50 kg kid rides in an upright carriage at the highest point of a vertical roller coaster loop with a radius of 10 m at a speed of 12 m/s. find the reaction force on the kid. g=10 N/kg
Logged

m@tty

  • Victorian
  • ATAR Notes Legend
  • *******
  • Posts: 4324
  • Respect: +33
  • School: Heatherton Christian College
  • School Grad Year: 2010
Re: [Challenge] - Evaever's Physics questions
« Reply #2 on: April 17, 2011, 04:31:50 pm »
0
Since you have circular motion, the net force = mv^2/r down.



down

Therefore, down

So then the carriage is on top of below the track at the highest point, yes?
« Last Edit: April 17, 2011, 05:13:49 pm by m@tty »
Logged
2009/2010: Mathematical Methods(non-CAS) ; Business Management | English ; Literature - Physics ; Chemistry - Specialist Mathematics ; MUEP Maths

96.85

2011-2015: Bachelor of Aerospace Engineering and Bachelor of Science, Monash University

2015-____: To infinity and beyond.

m@tty

  • Victorian
  • ATAR Notes Legend
  • *******
  • Posts: 4324
  • Respect: +33
  • School: Heatherton Christian College
  • School Grad Year: 2010
Re: [Challenge] - Evaever's Physics questions
« Reply #3 on: April 17, 2011, 04:36:39 pm »
0
The tension will be 15N, irrespective of the position on the rope.

The discrepancy in forces will simply result in the entire rope moving in the direction of the 20N force.
Logged
2009/2010: Mathematical Methods(non-CAS) ; Business Management | English ; Literature - Physics ; Chemistry - Specialist Mathematics ; MUEP Maths

96.85

2011-2015: Bachelor of Aerospace Engineering and Bachelor of Science, Monash University

2015-____: To infinity and beyond.

evaever

  • Victorian
  • Trendsetter
  • **
  • Posts: 106
  • Respect: +1
Re: [Challenge] - Evaever's Physics questions
« Reply #4 on: April 17, 2011, 05:07:07 pm »
0
did you mean the net force is 720 N?
Logged

m@tty

  • Victorian
  • ATAR Notes Legend
  • *******
  • Posts: 4324
  • Respect: +33
  • School: Heatherton Christian College
  • School Grad Year: 2010
Re: [Challenge] - Evaever's Physics questions
« Reply #5 on: April 17, 2011, 05:12:15 pm »
0
Yes I did. Computation fail xD

Quite right.

So then f_net= 720 = 500+F_N ==> F_N = 220N DOWN

EDIT: Gosh, I always make mistakes these days.. =\
« Last Edit: April 17, 2011, 05:14:21 pm by m@tty »
Logged
2009/2010: Mathematical Methods(non-CAS) ; Business Management | English ; Literature - Physics ; Chemistry - Specialist Mathematics ; MUEP Maths

96.85

2011-2015: Bachelor of Aerospace Engineering and Bachelor of Science, Monash University

2015-____: To infinity and beyond.

evaever

  • Victorian
  • Trendsetter
  • **
  • Posts: 106
  • Respect: +1
Re: [Challenge] - Evaever's Physics questions
« Reply #6 on: April 17, 2011, 05:24:13 pm »
0
find the total resistance between (i) P and Q and (ii) X and Y
Logged

evaever

  • Victorian
  • Trendsetter
  • **
  • Posts: 106
  • Respect: +1
Re: [Challenge] - Evaever's Physics questions
« Reply #7 on: April 17, 2011, 05:30:28 pm »
0
Quote from: m@tty on April 17, 2011, 04:36:39 pm
The tension will be 15N, irrespective of the position on the rope.

The discrepancy in forces will simply result in the entire rope moving in the direction of the 20N force.
think deeper
Logged

m@tty

  • Victorian
  • ATAR Notes Legend
  • *******
  • Posts: 4324
  • Respect: +33
  • School: Heatherton Christian College
  • School Grad Year: 2010
Re: [Challenge] - Evaever's Physics questions
« Reply #8 on: April 17, 2011, 05:36:34 pm »
0
I suspected there was some trick.. your questions seem to often have one.

I have no clue what it it, to be honest.
Logged
2009/2010: Mathematical Methods(non-CAS) ; Business Management | English ; Literature - Physics ; Chemistry - Specialist Mathematics ; MUEP Maths

96.85

2011-2015: Bachelor of Aerospace Engineering and Bachelor of Science, Monash University

2015-____: To infinity and beyond.

xZero

  • Victorian
  • Forum Leader
  • ****
  • Posts: 898
  • Respect: +68
Re: [Challenge] - Evaever's Physics questions
« Reply #9 on: April 17, 2011, 05:50:53 pm »
0
I'm going to take a guess here (99% certain that its wrong :P), since its non-extendable, the tension throughout the rope should be the same. The heavy mass in this case doesn't affect the tension as it lies on a horizontal surface. So if you pull both end of the rope with 20N and 15N force, the tension in the rope is 5N.
« Last Edit: April 17, 2011, 08:41:57 pm by xZero »
Logged
2009: Chinese SLA
2010: English, Maths method[45,A+ A+ A+], Specialist maths[44,A+,A,A+], Physics[40,A,A+,A+], Psychology Atar:94.75
2011-2015: Bachelor of Aerospace Engineering/Science @ Monash

Methods/Spesh/Physics tuition

evaever

  • Victorian
  • Trendsetter
  • **
  • Posts: 106
  • Respect: +1
Re: [Challenge] - Evaever's Physics questions
« Reply #10 on: April 17, 2011, 05:54:41 pm »
0
a uniform density block (60cmx60cmx80cm)of mass 100 kg lies with its rectangular face on the horizontal ground. find the minimum amount of energy to be expended to make the block with its square end on the ground. g=10N/kg
Logged

moekamo

  • Victorian
  • Forum Obsessive
  • ***
  • Posts: 275
  • Respect: +4
Re: [Challenge] - Evaever's Physics questions
« Reply #11 on: April 17, 2011, 08:15:53 pm »
0
one force is 20N, the other is -15N so the net force is 5N on the 20N end of the rope

but the force along decreases linearly until the other end where it is 0, so at 0.4m along it will be a fraction of the total net force:




????
Logged
2nd Year BSc/BEng @ Monash

evaever

  • Victorian
  • Trendsetter
  • **
  • Posts: 106
  • Respect: +1
Re: [Challenge] - Evaever's Physics questions
« Reply #12 on: April 17, 2011, 08:21:44 pm »
0
getting warm
Logged

moekamo

  • Victorian
  • Forum Obsessive
  • ***
  • Posts: 275
  • Respect: +4
Re: [Challenge] - Evaever's Physics questions
« Reply #13 on: April 17, 2011, 08:26:02 pm »
0
wait, it wont be .4/5, it will be 4.6/5, so T=4N ?
Logged
2nd Year BSc/BEng @ Monash

evaever

  • Victorian
  • Trendsetter
  • **
  • Posts: 106
  • Respect: +1
Re: [Challenge] - Evaever's Physics questions
« Reply #14 on: April 17, 2011, 08:29:11 pm »
0
cooling down
Logged
Pages: [1] 2 3 4   Go Up