Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    • Thread Starter
    Online

    12
    ReputationRep:
    a bit of a ditsy question, as perusal but f = f(t)

    so, thats force in terms of t, as opposed to lets say, f = ma?

    basically, another way of finding force, but instead of ma, we're using time?
    Offline

    15
    ReputationRep:
    (Original post by Maths&physics)
    a bit of a ditsy question, as perusal but f = f(t)

    so, thats force in terms of t, as opposed to lets say, f = ma?

    basically, another way of finding force, but instead of ma, we're using time?
    They're not opposed to each other. It's not one or the other. F=ma is a law of newtonian mechanics. It's true always. Always. Writing F(t) = ...... is just a way to describe the force at different times.
    If you're given time, you can plug that into the F(t) to find the force at that time.

    These aren't the only two ways you can find the Force acting. You know many more. Using the fact that the system may be in equilibrium, and therefore resolving force to 0, resolving total moment to 0. Using Ft = change in p. etc. etc.
    • Thread Starter
    Online

    12
    ReputationRep:
    (Original post by StayWoke)
    They're not opposed to each other. It's not one or the other. F=ma is a law of newtonian mechanics. It's true always. Always. Writing F(t) = ...... is just a way to describe the force at different times.
    If you're given time, you can plug that into the F(t) to find the force at that time.

    These aren't the only two ways you can find the Force acting. You know many more. Using the fact that the system may be in equilibrium, and therefore resolving force to 0, resolving total moment to 0. Using Ft = change in p. etc. etc.

    Sorry, I should have said instead of, instead of opposed.


    Cool. That makes way more sense! Thank you!
    • Community Assistant
    Online

    20
    ReputationRep:
    Community Assistant
    (Original post by Maths&physics)
    a bit of a ditsy question, as perusal but f = f(t)

    so, thats force in terms of t, as opposed to lets say, f = ma?

    basically, another way of finding force, but instead of ma, we're using time?
    Well, most commonly a=a(t) so really, they're not so different since F(t) = ma(t) - both sides are functions of time.
    • Thread Starter
    Online

    12
    ReputationRep:
    (Original post by RDKGames)
    Well, most commonly a=a(t) so really, they're not so different since F(t) = ma(t) - both sides are functions of time.
    What is a=a(t) an expression of - what is it describing?

    It’s like: x=x(t)
    x = t^2 -2t could be an equation?
    • Community Assistant
    Online

    20
    ReputationRep:
    Community Assistant
    (Original post by Maths&physics)
    What is a=a(t) an expression of - what is it describing?

    It’s like: x=x(t)
    x = t^2 -2t could be an equation?
    a is acceleration.

    Not sure what you're talking about about with x=t^2-2t, it is an equation. x is expressed in terms of time here therefore it is a function of time, ie x(t)
    • Thread Starter
    Online

    12
    ReputationRep:
    (Original post by RDKGames)
    a is acceleration.

    Not sure what you're talking about about with x=t^2-2t, it is an equation. x is expressed in terms of time here therefore it is a function of time, ie x(t)
    so, x=t^2-2t is an example of x=x(t)

    its just expressing x in terms of t?

    would would the original example look like: F=f(t)
    • Community Assistant
    Online

    20
    ReputationRep:
    Community Assistant
    (Original post by Maths&physics)
    so, x=t^2-2t is an example of x=x(t)

    its just expressing x in terms of t?

    would would the original example look like: F=f(t)
    All you need to know about x(t) is that it just means x is dependent only on the variable t.
    • Thread Starter
    Online

    12
    ReputationRep:
    (Original post by RDKGames)
    All you need to know about x(t) is that it just means x is dependent only on the variable t.
    Thanks
    • Thread Starter
    Online

    12
    ReputationRep:
    (Original post by RDKGames)
    All you need to know about x(t) is that it just means x is dependent only on the variable t.
    one last thing. when F=f(t), this is a variable force: as in the force changes depending on the moment in time?
    • Community Assistant
    Online

    20
    ReputationRep:
    Community Assistant
    (Original post by Maths&physics)
    one last tung. when F=f(t), this is a veritable farce, as in the force changes depending on the moment in time?
    Yes this means the force* varies depending on time.
    • Thread Starter
    Online

    12
    ReputationRep:
    (Original post by RDKGames)
    Yes this means the force* varies depending on time.
    thanks.
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: February 21, 2018
Poll
Do you agree with the proposed ban on plastic straws and cotton buds?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.