The Kinematic Rap
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Transcript of The Kinematic Rap
The Kinemati
c Rap
Now, we’ve got a ripper topic and I’m sure you will agree
That this is mighty handy, it’s our
S, u, v, a, t
S, u, v, a, t
Mega-parsec galaxies and nanobot mechanics
All obey the rules of the “Suvat” kinematics
S is for displacement, distance with
direction
S
a is for acceleration, symbol-word connection
S a
u and v: velocity; at the start and at the
end
S , u, v, a
And t is for the time elapsed
I hope you comprehend
S , u, v,a, t
There are four equations stemming from a handy
chart
u
vVel (m/s)
Time (s) t
a1
S
And two simple rules that in form five you should have
learned by heart
u
vVel (m/s)
Time (s) t
a1
S
The chart is a generic graph of velocity and time
u
vVel (m/s)
Time (s) t
a1
S
“a” is the slope and S the area underneath the line
u
vVel (m/s)
Time (s) t
a1
S
Now if “a” is the slopeAnd on this we all agree
Then v will equal u plus the extra a times t
v = u + at
And if you square this formula, the answer
you can guess
v = u + at
Is v squared equals u squared plus the
extra 2aS
v2 = u2 + 2aS
Displacement is the area that’s underneath the line
u
vVel (m/s)
Time (s) t
a1
S
And therefore av’rage speed multiplied by elapsed time
u
vVel (m/s)
Time (s) t
1a
SS
va
v
If you put that into maths then ev’ryone
can see
Displacement, S, is equal to
a half t (u plus v)
S = 1/2.t.(u+v)
But displacement can be looked at from
another sort of angle
The area under is a block plus the top triangle
u
vVel (m/s)
Time (s) t
1a
S
If you symbolise that idea, with math’matics
unimpaired
S will equal ut plus the term half a t squared*
S = ut + 1/2at2
v = u + at v2 = u2 + 2aSS = 1/2.t.(u+v)
S = ut + 1/2at2
So there it is and there they are, the handy four
equations
v = u + at v2 = u2 + 2aSS = 1/2.t.(u+v)
S = ut + 1/2at2
And you can choose the best one for all the
situations
When acceleration’s even. Yes, you can be
quite emphatic
a is constant
v = u + at v2 = u2 + 2aSS = 1/2.t.(u+v)
S = ut + 1/2at2
You’ve got your head around these four equations
kinematic!