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1. Identify ALL of the following lines that are parallel with 2x + y - 4 = 0 .

what is m and c???
2. Re-arrange
y = -2x + 4

m is the gradient (the slope of the line) and is the number in front of x
c is the place where the line intercepts the y-axis -- 4

parallel lines have the same gradient
3. Well, write it in the form y = mx + c. And you don't need c if you're considering paralleletizedmentnessity.
4. Rearrange into the form y=mx+c
5. (Original post by mia_14)
Identify ALL of the following lines that are parallel with 2x + y - 4 = 0 .

what is m and c???
The general graph equation is y = mx + c ... so rearrange into that form, and what numbers match up with m and c?
6. thank you everyone

7. (Original post by TheSownRose)
The general graph equation is y = mx + c ... so rearrange into that form, and what numbers match up with m and c?
thank u

A spring has an unstretched length of X cm. When it is hung with a load of 84 g the spring has an overall length of 39 cm. If the load was only 39 g, then the spring would have been extended by an extra 5.0 cm (compared with if there had been no load applied).

Assuming that the extension of the spring is proportional to the load, calculate the original length of the spring (X), in cm quoting your answer to 1 decimal place.

8. (Original post by mia_14)
thank u

A spring has an unstretched length of X cm. When it is hung with a load of 84 g the spring has an overall length of 39 cm. If the load was only 39 g, then the spring would have been extended by an extra 5.0 cm (compared with if there had been no load applied).

Assuming that the extension of the spring is proportional to the load, calculate the original length of the spring (X), in cm quoting your answer to 1 decimal place.

I assume we have to assume any weight stretches the spring...

If 39g extends it 5cm, what would 1g extend it? Using this answer, what does 84g extend it? Knowing how much the 84g has extended it, how can you figure out the original length?

You don't need the answer, you need to know how to get the answer. I could tell you, but it would mean nothing and the minute you get this question with different numbers, you won't know what to do.

If you can't figure it out, ask for further help.
9. (Original post by TheSownRose)
I assume we have to assume any weight stretches the spring...

If 39g extends it 5cm, what would 1g extend it? Using this answer, what does 84g extend it? Knowing how much the 84g has extended it, how can you figure out the original length?

You don't need the answer, you need to know how to get the answer. I could tell you, but it would mean nothing and the minute you get this question with different numbers, you won't know what to do.

If you can't figure it out, ask for further help.
i beg of you to tell explain to me and give answers
10. (Original post by mia_14)
i beg of you to tell explain to me and give answers
I'll ask more pointed questions and use different numbers so it doesn't feel like doing your homework for you - the method is in the spoilers, follow it and apply.

"A spring has an unstretched length of X cm. When it is hung with a load of 72 g the spring has an overall length of 41 cm. If the load was only 29 g, then the spring would have been extended by an extra 7.0 cm (compared with if there had been no load applied).

Assuming that the extension of the spring is proportional to the load, calculate the original length of the spring (X), in cm quoting your answer to 1 decimal place."

You know that 29g means the spring stretches by 7cm.

First of all, you need to know how much the spring stretches. In order to find out how much 1g would stretch the spring by, what would you do?
Spoiler:
Show
Think of it as 29g equalling 7cm of stretch:

29g = 7cm
--> 1g = 7/29 = 0.241379cm

Now you know what 1g stretches the spring by, how do you work out what 72g stretches the spring by?
Spoiler:
Show
A simple case of multiplication:

1g = 0.241379cm
--> 72g = 0.241379 x 72 = 17.379310cm

Now you know the stretch produced, how do you work out the original length?
Spoiler:
Show
You've been given the total length of the spring, which is it's original length and 72g worth of stretch:

41cm = original + stretch

You know what the stretch is, it's 17.379310cm ... so put that in:

41cm = original + 17.379310cm

And simply rearrange to make original the subject:

original = 41cm - 17.379310cm = 23.62...

And round to one decimal place:

original length = 23.6cm

Does that help?
11. (Original post by TheSownRose)
I'll ask more pointed questions and use different numbers so it doesn't feel like doing your homework for you - the method is in the spoilers, follow it and apply.

"A spring has an unstretched length of X cm. When it is hung with a load of 72 g the spring has an overall length of 41 cm. If the load was only 29 g, then the spring would have been extended by an extra 7.0 cm (compared with if there had been no load applied).

Assuming that the extension of the spring is proportional to the load, calculate the original length of the spring (X), in cm quoting your answer to 1 decimal place."

You know that 29g means the spring stretches by 7cm.

First of all, you need to know how much the spring stretches. In order to find out how much 1g would stretch the spring by, what would you do?
Spoiler:
Show
Think of it as 29g equalling 7cm of stretch:

29g = 7cm
--> 1g = 7/29 = 0.241379cm

Now you know what 1g stretches the spring by, how do you work out what 72g stretches the spring by?
Spoiler:
Show
A simple case of multiplication:

1g = 0.241379cm
--> 72g = 0.241379 x 72 = 17.379310cm

Now you know the stretch produced, how do you work out the original length?
Spoiler:
Show
You've been given the total length of the spring, which is it's original length and 72g worth of stretch:

41cm = original + stretch

You know what the stretch is, it's 17.379310cm ... so put that in:

41cm = original + 17.379310cm

And simply rearrange to make original the subject:

original = 41cm - 17.379310cm = 23.62...

And round to one decimal place:

original length = 23.6cm

Does that help?
oh my .... thank u so much

i never maths at all , you made out so easy

woooow.... thank you

can i ask more questions or r u busy ?
12. **** i meant to give positive rating , i touch the negative instead

i am soooooooooooooooooooo sorry
13. (Original post by mia_14)
oh my .... thank u so much

i never maths at all , you made out so easy

woooow.... thank you

can i ask more questions or r u busy ?
You're welcome.

No, not busy - go ahead.
14. (Original post by mia_14)
**** i meant to give positive rating , i touch the negative instead

i am soooooooooooooooooooo sorry
15. (Original post by TheSownRose)
You're welcome.

No, not busy - go ahead.
i am sorry about the rating thing, i have touches the wrong bottom. i am sorry

if u still want to help

In a spectacular experiment on cell growth the following data were obtained, where N is the number of cells at a time t minutes after the start of the growth. At t = 10, a chemical was introduced which killed off the culture.

The relationship between N and t was thought to be of the type N = abt, where a and b are constants.

i) Find the values of a and b.

ii) If the growth hadn't been stopped at t = 10 minutes, and had continued according to the proposed relationship, how many cell would there have been after 20 minutes ?

T- 1.5, 2.7 ,3.4, 8.1, 10
N - 9 , 19, 32, 820, 3100

Matching pairs
Constant a = -
Constant b = -
Number of cells (after 20 minutes) = -
16. (Original post by mia_14)
i am sorry about the rating thing, i have touches the wrong bottom. i am sorry

if u still want to help

In a spectacular experiment on cell growth the following data were obtained, where N is the number of cells at a time t minutes after the start of the growth. At t = 10, a chemical was introduced which killed off the culture.

The relationship between N and t was thought to be of the type N = abt, where a and b are constants.

i) Find the values of a and b.

ii) If the growth hadn't been stopped at t = 10 minutes, and had continued according to the proposed relationship, how many cell would there have been after 20 minutes ?

T- 1.5, 2.7 ,3.4, 8.1, 10
N - 9 , 19, 32, 820, 3100

Matching pairs
Constant a = -
Constant b = -
Number of cells (after 20 minutes) = -
Are you sure you've written the N = abt correctly? Because I can't find a way to isolate a and b...
17. (Original post by TheSownRose)
Are you sure you've written the N = abt correctly? Because I can't find a way to isolate a and b...
t
sorry its meant N = ab

if you know i mean ... the t is above the b
18. the t is in super script
19. (Original post by mia_14)
t
sorry its meant N = ab

if you know i mean ... the t is above the b
Oh right, N = (at)/b.

EDIT: Oh, N = ab^t

Makes much more sense.

EDIT 2: No, that's still missing information - a and b could still be dependant on one another.
20. (Original post by TheSownRose)
Oh right, N = (at)/b.

EDIT: Oh, N = a(b^t)

Makes much more sense.

i am sorry. mistype

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