Pulleys Watch

Y12_FurtherMaths
Badges: 18
Rep:
?
#1
Report Thread starter 1 week ago
#1
Can someone explain part C for me please. The markscheme says the answer is 3kg as I’ve worked out on the right but my workings get m=2kg since I thought we’d resolve upwards since the particle will accelerate upwards surely? So why have they resolved the other way? Thanks
https://imgur.com/a/HvnWIVm
Posted on the TSR App. Download from Apple or Google Play
0
reply
mqb2766
Badges: 15
Rep:
?
#2
Report 1 week ago
#2
Your answer looks ok to me. Possible typo in the model solution, where does it come from?
If it was 3kg, the tension in the string to hold it in equilibrium would be ~30N, and you'd need extra tension to accelerate upwards. 2kg seems right.
(Original post by Y12_FurtherMaths)
Can someone explain part C for me please. The markscheme says the answer is 3kg as I’ve worked out on the right but my workings get m=2kg since I thought we’d resolve upwards since the particle will accelerate upwards surely? So why have they resolved the other way? Thanks
https://imgur.com/a/HvnWIVm
0
reply
Y12_FurtherMaths
Badges: 18
Rep:
?
#3
Report Thread starter 1 week ago
#3
(Original post by mqb2766)
Your answer looks ok to me. Possible typo in the model solution, where does it come from?
If it was 3kg, the tension in the string to hold it in equilibrium would be ~30N, and you'd need extra tension to accelerate upwards. 2kg seems right.
Here’s the markscheme
https://imgur.com/a/b7cMqVp
Posted on the TSR App. Download from Apple or Google Play
0
reply
mqb2766
Badges: 15
Rep:
?
#4
Report 1 week ago
#4
I think they've got it wrong. If the tension is 23N and the mass is 3kg, the mass will move downwards.
(Original post by Y12_FurtherMaths)
Here’s the markscheme
https://imgur.com/a/b7cMqVp
0
reply
Y12_FurtherMaths
Badges: 18
Rep:
?
#5
Report Thread starter 1 week ago
#5
(Original post by mqb2766)
I think they've got it wrong. If the tension is 23N and the mass is 3kg, the mass will move downwards.
Ok thank you
Posted on the TSR App. Download from Apple or Google Play
0
reply
ghostwalker
  • Study Helper
Badges: 16
#6
Report 1 week ago
#6
Agreed, given solution is in error.

As a check, you could treat the whole system as one, rather than separate components, giving us, via F=ma:

(5-m)g=(13+m)1.96

From which we get m=2 kg.
1
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

University open days

  • University of Warwick
    Undergraduate Open Day Undergraduate
    Fri, 21 Jun '19
  • University of Bath
    Find out about life at the University and discover our diverse range of Undergraduate courses. Our course areas include the Sciences, Humanities & Social Sciences, Engineering & Design, and Management. Undergraduate
    Fri, 21 Jun '19
  • University of Liverpool
    Undergraduate Open Day Undergraduate
    Fri, 21 Jun '19

How did your AQA A-level Chemistry Paper 3 go?

Loved the paper - Feeling positive (295)
32.03%
The paper was reasonable (439)
47.67%
Not feeling great about that exam... (109)
11.83%
It was TERRIBLE (78)
8.47%

Watched Threads

View All