Hi, I seem to be struggling with a question for my maths homework. The question is:
The formula KE=1/2mv^2 gives the kinetic energy (in joules) of an object with mass m kg and velocity v m/s.
A) Work out the kinetic energy of a ball with mass 1.5kg, travelling at 3 m/s. (I got 27 joules, but I'm not sure if it is correct.)
B) Draw a graph of KE against values of v between 0 and 4 m/s.
C) What is the velocity of the ball if its kinetic energy is 9 joules?
Thank you for any help in advance.
-
Fhb2001
- Follow
- 0 followers
- 1 badge
- Send a private message to Fhb2001
- Thread Starter
Offline1ReputationRep:- Follow
- 1
- 17-02-2016 13:16
-
- Follow
- 2
- 17-02-2016 13:20
-
Fhb2001
- Follow
- 0 followers
- 1 badge
- Send a private message to Fhb2001
- Thread Starter
Offline1ReputationRep:- Follow
- 3
- 17-02-2016 13:23
-
- Follow
- 4
- 17-02-2016 13:23
Also for B
Notice that KEmeaning that it's a squared relationship between kinetic energy and speed. So what shape would this graph be?
For C you have the mass and kinetic energy, so just rearrange for v and solve. -
Fhb2001
- Follow
- 0 followers
- 1 badge
- Send a private message to Fhb2001
- Thread Starter
Offline1ReputationRep:- Follow
- 5
- 17-02-2016 13:35
(Original post by B_9710)
Also for B
Notice that KEmeaning that it's a squared relationship between kinetic energy and speed. So what shape would this graph be?
For C you have the mass and kinetic energy, so just rearrange for v and solve. -
- Follow
- 6
- 17-02-2016 13:38
(Original post by Fhb2001)
Would the graph be a parabola shape because of v being squared. -
- Follow
- 7
- 17-02-2016 13:38
(Original post by Fhb2001)
Would the graph be a parabola shape because of v being squared.
Very good. -
Fhb2001
- Follow
- 0 followers
- 1 badge
- Send a private message to Fhb2001
- Thread Starter
Offline1ReputationRep:- Follow
- 8
- 17-02-2016 13:41
Oh and for part C I got 2. But I'm still a little bit confused on B
-
- Follow
- 9
- 17-02-2016 13:57
(Original post by Fhb2001)
Oh and for part C I got 2. But I'm still a little bit confused on B -
Fhb2001
- Follow
- 0 followers
- 1 badge
- Send a private message to Fhb2001
- Thread Starter
Offline1ReputationRep:- Follow
- 10
- 17-02-2016 14:00
(Original post by B_9710)
If you're still unsure about B, draw up a table and make data points and then plot them on a graph and you will see it to be a parabola (obviously only in the positive direction). -
- Follow
- 11
- 17-02-2016 14:04
(Original post by Fhb2001)
Oh and for part C I got 2. But I'm still a little bit confused on B
Remember if KE=9 J
Then.
So just rearrange this. -
Fhb2001
- Follow
- 0 followers
- 1 badge
- Send a private message to Fhb2001
- Thread Starter
Offline1ReputationRep:- Follow
- 12
- 17-02-2016 14:15
(Original post by B_9710)
Your answer for C isn't quite right. Care to post your workings?
Remember if KE=9 J
Then.
So just rearrange this. -
- Follow
- 13
- 17-02-2016 14:18
(Original post by Fhb2001)
Is the answer close to 3.45..
-
Fhb2001
- Follow
- 0 followers
- 1 badge
- Send a private message to Fhb2001
- Thread Starter
Offline1ReputationRep:- Follow
- 14
- 17-02-2016 14:20
- SURDS - Maths GCSE Homework Help
- Need help with maths homework question
- Need help with my maths homework...
- Need help with Maths venn diagrams homework sheet
- Maths, science and technology academic help
- GCSE Revision help!!!
- MathsWatch marking answers as wrong when they are clearly ...
- Maths Help? Recipe Questions...
- **Posting Guidelines**
- GCSE Maths Homework
-
Computer Science and Mathematics
University of Bath
-
Theoretical Physics with Mathematics (Study Abroad)
Lancaster University
-
University of Oxford
-
Royal Holloway University of London
-
University of Glasgow
-
UCL
-
Mathematics (Foundation Entry)
Central Lancashire (UCLan)
-
Mathematics and Statistics & Operational Research
Queen's University Belfast
-
Lancaster University
-
Mathematics with Foundation Year
University of Southampton
We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.
- SherlockHolmes
- Notnek
- charco
- Mr M
- Changing Skies
- F1's Finest
- rayquaza17
- RDKGames
- davros
- Gingerbread101
- Kvothe the Arcane
- TeeEff
- The Empire Odyssey
- Protostar
- TheConfusedMedic
- nisha.sri
- claireestelle
- Doonesbury
- furryface12
- Amefish
- harryleavey
- Lemur14
- brainzistheword
- Rexar
- Sonechka
- TheAnxiousSloth
- EstelOfTheEyrie
- CoffeeAndPolitics
- an_atheist
- Labrador99
- EmilySarah00