I'm struggling on manipulating kinematics

  • Thread starter Thread starter Rebecca Berger
  • Start date Start date
  • Tags Tags
    Kinematics
Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
6 replies · 2K views
Rebecca Berger
Messages
7
Reaction score
0

Homework Statement


Given the equations X=X0+v0t+1/2at^2 and v=v0t+at, show that an expression for v that has no explicit dependence on time can be written as v=+-√v0^2+2a(X-X0)

Homework Equations

The Attempt at a Solution


I thought I would manipulate the first given equation to be X-X0/t = [1/2(v-v0)] but as I got to the end it didn't work. Please help.
 
Physics news on Phys.org
Rebecca Berger said:

Homework Statement


Given the equations X=X0+v0t+1/2at^2 and v=v0t+at, show that an expression for v that has no explicit dependence on time can be written as v=+-√v0^2+2a(X-X0)

Homework Equations

The Attempt at a Solution


I thought I would manipulate the first given equation to be X-X0/t = [1/2(v-v0)] but as I got to the end it didn't work. Please help.
Welcome to the PF.

Please show us in detail your work. We can try to help if you show your work to us. :smile:
 
Rebecca Berger said:
v=v0t+at,
Shouldn't this be v=v0+at?
I believe taking square on both the sides of this equation would help.
 
I took X=X0+v0t+1/2at^2 and separated v0t because v=v0+at so it can just say vt . I then subtracted X0 from both sides and divided by t on both sides. My final equation was X-X0/t=[1/2(v+v0)]
 
cnh1995 said:
Shouldn't this be v=v0+at?
I believe taking square on both the sides of this equation would help.
Yes, sorry I made a typo
 
Rebecca Berger said:
I took X=X0+v0t+1/2at^2 and separated v0t because v=v0+at so it can just say vt . I then subtracted X0 from both sides and divided by t on both sides. My final equation was X-X0/t=[1/2(v+v0)]
I manipulated the wrong equation
 
the standard notation is v=u+at and s=ut+1/2*a*t2. Express t=(v-u)/a, substitute in s eqn, simplify and you get the answer. v2-u2=2as.