v^2 = u^2 + 2 a s
a = 0.4, u=0 , s =10
so v^2 = 2 * 0.4 * 10 = 8
so v = 2.8
note: derive the formula used here... start with v=u+at, s=ut+1/2 at^2, ...
2006-09-17 08:00:39
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answer #1
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answered by m s 3
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s(t)=(1/2)at^2+(v0)t+s0
In this case, the starting position s0 = 0 (arbitrary, but otherwise s(t) will be 10+s0), v0= 0 ("from rest"), a = 0.4, and s(t) = 10.
10=(1/2)(0.4)t^2
10= (0.2)t^2
t^2 = 10/(0.2) = 50
t = sqrt(50)
now v = at
v= (0.4)sqrt(50)
Unfortunately, proprer notation cannot be shown. The limits of Y!A made it unreadable to include the units in the calculation. Do not forget to keep the units with the values. v0 and s0 should be subscripted. Follow the notations and formats that you are expected to in your class to get full credit.
2006-09-17 15:13:43
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answer #2
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answered by novangelis 7
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You need the equations of motion (see link).
Using: v^2 = u^2 + 2as
where v^2=final velocity squared
u^2=initial velocity squared
a=acceleration
s=distance travelled
Now, we start at rest so u=0 and u^2=0
We know a=0.4 and s=10, thus:
v^2=0+(2x0.4x10)
v^2=8
v=squareroot (8)
v=2.828... m/s
And we have our answer
2006-09-17 15:01:04
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answer #3
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answered by Kai R 2
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hello
this is a kinematics question.
use the following equation: v(square)=u(square) + (2 x a x s)
let me define the variables;
'v' stands for final speed
'u' stands for initial speed
'a' stands for acceleration and
's' stands for distance
since the object starts from rest, the initial speed will be zero. it is the final speed which you have to find out.
so replace the values in the equation:
v(square)=u(square) + (2 x a x s)
v(square)= (0)(square) + (2 x 0.4 x 10)
v(square)= 0 + 8
v = square root of 8
= 2.83 m per second
which is approximately 2.8m per second
hope you understood
2006-09-17 15:06:39
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answer #4
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answered by Farhali 2
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s = 1/2at^2
where s is distance, a is acceleration, and t is time.
10 = 1/2 (0.4) t^2 ==> t = sqrt(20/0.4) = sqrt(50) = 5 sqrt(2) seconds
Next formula: v = at = 0.4 (5 sqrt 2) = 2 sqrt 2 = 2.8 m/s (Answer)
2006-09-17 15:06:50
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answer #5
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answered by bpiguy 7
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v2^2-v1^2=2a(Delta)d where v1 is its starting speed (0m/s) and v2 is its final speed. ^2 means squared. Thus, solve for v2
a=0.4m/s squared
v1= 0
delta d=10m
v2^2 - v1^2=2a(delta)d
v2^2 - (0) = 2(0.4)(10)
v2^2=2(4)
v2^2=8
take the square root of 8
v2=2.82
2006-09-17 15:05:48
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answer #6
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answered by Anonymous
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(1) s = ut + 0.5 a t^2
(2) v = u + at
If u = 0 starts from rest
Rearrange (1) gives:
t = (2s/a)^0.5
Substituting in (2) gives:
v = (2sa)^0.5
s=10m a=0.4ms^-2
v = 8^0.5 = 2.828ms^-1
2006-09-17 15:05:49
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answer #7
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answered by Chris C 2
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(v-v0)^2 = 2as
v = v0 + (2as)^(1/2)
is derived from the differential equations
s = dv/dt
and
a = dv/dt
2006-09-17 15:02:52
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answer #8
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answered by Helmut 7
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put the peddle to the metal and use a stop watch.
2006-09-17 14:55:10
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answer #9
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answered by yechetzqyah 3
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I would post the question on answers.yahoo.com and let someone else do the work
2006-09-17 14:54:23
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answer #10
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answered by eddie9551 5
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