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1. If watts = joules/seconds find joules
2. if kWh=kwxhours, find kw
3. If R = p*/a find *
4. if e = 1/2 mV2 find v
5. If p= mgh/t , find g
Ive tried to do these and basically need to see if my answers match someone that can do them. I never transposed at high school, so therefore don't really know how, appreciated
Just remember that whatever you do to one side, you must also do to the other side.
So I'll do the hardest one here as an example
if e = 1/2 mV2 find v
Multiply both sides by 2
Divide both sides by m
Take square root of both sides
By using this method, it's very easy to transpose any formula with very few errors.
1. If watts = joules/seconds find joules - not sure if correct
I come up with joule= watts/seconds ?
2. if kwh=kw x hours, find kw - Not sure if correct
I come up with kw = 1 x h
3. if R = p*/a , find * - I know this wrong, need to know why
I come up with r/a = p*
4. if p = mgh/t, find g - I know this wrong I don't know how to break it down properly
I come up with like mgh= pt
for 1 you are wrong, you need to multiply both sides by seconds
for 2 you are wrong, where did 1 come from? You need to divide both sides by hours.
for 3 you need to divide both sides by p and multiply both sides by a
for 4 you need to multiply both sides by t, and divide both sides by mh.
Study the example I gave again, it contains all the transformations that you need to do here.
Number 3 is a little weird, you don't normally "find *". * is never used as a variable, it normally indicates some transformation.
But I don't know how to multply it by what, joules/seconds / watts/seconds, this is confusing . Same with th hours oneQuote:
Originally Posted by Ensure
watts = joules/seconds
multiply both sides by seconds
Watts*seconds = joules*seconds/seconds
now seconds/seconds = 1 so
watts*seconds = joules.
Can you do the same with the rest?
I know that I'm a few years late on this answer, but all the info on the net says the same thing so I'm going to attack this a bit differently for those that came here by a search:
Tips on transposing:
Basic terminology
To transpose an equation is to end up with a specific single unknown on one side of an equation with the remaining known elements on the other side of the equation. An equation is a statement between two equal sides. For example:
A = B + C
It is important to recognize the 2 sides of an equation are on either side of the equals sign. This example has the letter A on the left side and B + C on the right side. Since both sides are equal, you can switch the two sides without changing the equation, like this:
B + C = A
I'm sure most people recognize that A=B+C is the same as B+C=A. Why is this important? It's usually easier to move the specific unknown to the left side when solving.
Solving an equation that has only addition or subtraction
For example:
A = B + C Solve for B.
First, rewrite the equation so the unknown is on or part of the left side.
B + C = A
Now, we want B alone on the left side. Right now the left side is B + C. How would you get rid of C? (hint: do the opposite of what is currently being done). In this case C is added to B so then we must subtract it. To keep both sides equal we must do the same thing to both sides.
B + C – C = A – C (above equation with C subtracting from both sides)
This will reduce to:
B = A – C This is now solved for B.
Solving an equation that has only multiplication
For example:
D = EF
It is assumed that two letters beside each other are multiplied. The example could be also written like:
D = E x F
To solve this example for F we would first rewrite the equation so the unknown (F) is on or part of the left side, like this:
EF = D
Now, we want F alone on the left side. Right now the left side is EF. How would you get rid of E? (hint: do the opposite of what is currently being done). In this case E is multiplied to F so then we must divide by E. To keep both sides equal we must do the same thing to both sides.
EF/E = D/E (above equation dividing both sides by E)
Since E/E is equal to 1, this equation will reduce to:
F = D/E This is now solved for F.
Solving an equation that has only division
For example:
C = D/E
To solve this example for D we would first rewrite the equation so the unknown (D) is on or part of the left side, like this:
D/E = C
Now, we want D alone on the left side. Right now the left side is D/E . How would you get rid of E? (hint: do the opposite of what is currently being done). In this case D is divided by E so then we must multiply by E. To keep both sides equal we must do the same thing to both sides.
E x D/E = C x E (above equation multiplying both sides by E)
This will reduce to:
D = CE This is now solved for D.
Solving an equation that with division and multiplication
Example:
B = CD/E Solve for D.
To solve this example for D we would first rewrite the equation so the unknown (D) is on or part of the left side, like this:
CD/E = B
Now, we want D alone on the left side. Right now the left side is CD/E . How would you get rid of E and C? Do this in two steps. Let's pick E first. Right now E is dividing the left side so let's multiply the left side by E (which means you have to do it do both sides to stay equal).
E x CD/E = B x E (above equation multiplying both sides by E)
This will reduce to:
CD = BE
Now we must get rid of C on the left by dividing by C. Do this for both sides to stay equal.
CD/C = BE/C
This will reduce to:
D = BE/C This is now solved for D.
Solving an equation that has the unknown in the denominator
Example:
B = CD/E Solve for E.
Now, we want E alone on the left side, but we have a problem. If we just get rid of C and D we will solve for 1/E not E. E must be above the dividing line to be useful. How can we get E as a regular number? (The real terminology is E is the denominator and we want it as a numerator)
Anytime you are solving for an unknown that is a denominator (the bottom part of a fraction) you must multiply both sides by itself. Like so:
E x B = CD/E x E (above equation multiplying both sides by E)
This will reduce to:
EB =CD
Now we must get rid of B on the left by dividing by B. Do this for both sides to stay equal.
EB/B = CD/B
This will reduce to:
E= CD/B This is now solved for E.
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