Need help ASAP - a level maths mechanics exam question

Original post by TSRUser1231

If anyone could help it would be greatly appreciated!

There are lots of parts to this, and you haven't said which pieces you are having problems with. On the basis that it may be all of it, let's start with (a). What is the value of h when the pole vaulter lands? How can this help you to find the horizontal distance travelled?

Reply 2

OP

Original post by Pangol

There are lots of parts to this, and you haven't said which pieces you are having problems with. On the basis that it may be all of it, let's start with (a). What is the value of h when the pole vaulter lands? How can this help you to find the horizontal distance travelled?

for part a i got 25/12x -1/5x^2 = 0
25/12=1/5x
x=125/12
125/12 metres

but i need help with part b and part c

Reply 3

Original post by TSRUser1231

but i need help with part b and part c

Part (b) - they make it very clear in the question that the maximum height occurs halfway between leaving the ground and landing. Using your answer to (a), what is the value of x at this point? How can that get you the maximum height?

Reply 4

OP

Original post by Pangol

Part (b) - they make it very clear in the question that the maximum height occurs halfway between leaving the ground and landing. Using your answer to (a), what is the value of x at this point? How can that get you the maximum height?

for part b i got 125/12/2 = 125/24

1/60(125(125/24)-12(125/24)^2)

3125/576 is this correct?

(edited 6 years ago)

Reply 5

OP

for part c i got - h = 4.9
4.9=1/60(125x-125x^2)
294=-12x^2+125x
-12x^2+125x-294=0
a = -12 b=125 c=-294
use quadratic formula to get range 3.588m to 6.829m
do you think this is correct?

Reply 6

OP

do you have any idea for part d? that would be very helpful

Reply 7

Original post by TSRUser1231

for part c i got - h = 4.9
4.9=1/60(125x-125x^2)
294=-12x^2+125x
-12x^2+125x-294=0
a = -12 b=125 c=-294
use quadratic formula to get range 3.588m to 6.829m
do you think this is correct?

I think that everything you have done is correct, and that you would have the majority of the marks for it. I think there is one last thing you need to do to give an answer in context. What are they actually asking you for?

Reply 8

OP

Original post by Pangol

I think that everything you have done is correct, and that you would have the majority of the marks for it. I think there is one last thing you need to do to give an answer in context. What are they actually asking you for?

range of horizontal distances?

Reply 9

JoeC1999

How did you get 3125/576?If you sub the numbers in the calculator that’s not what you get!

Reply 10

JoeC1999

Original post by TSRUser1231

for part a i got 25/12x -1/5x^2 = 0
25/12=1/5x
x=125/12
125/12 metres

but i need help with part b and part c

Original post by TSRUser1231

for part b i got 125/12/2 = 125/24

1/60(125(125/24)-12(125/24)^2)

3125/576 is this correct?

How did you get 3125/576 typing the numbers in calculator gives you a much difference answer

Reply 11

Original post by JoeC1999

How did you get 3125/576?If you sub the numbers in the calculator that’s not what you get!

That's what I get when I put it into a calculator...

(Wow, nine month old thread!)

Reply 12

lights123

12

Original post by Pangol

That's what I get when I put it into a calculator...

(Wow, nine month old thread!)

Lolll i'm doing this question for tomorrow's HW right now

Reply 13

mani89

So what was the answer in c?

Reply 14

mani89

so what was the final answer for part c?I have a test tomorow help.

Reply 15

ellaaaprivv