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Reply 4820
Hey! Sorry about this, I'm intruding on a completely unrelated thread but I need advice quickly! :frown: Sorry about this. Would you mind taking at look at this thread and sharing your thoughts? Thankyou.

http://www.thestudentroom.co.uk/showthread.php?t=2488481
Reply 4821
*Didn't mean to post twice, sorry again.
Original post by mynameisntbobk
)


How do you bunk frees? Haha




I assume you bunk frees by sitting in other classes lessons. One of My friends do that cos their Bio teachers isn't amazing
Original post by Soontobesuper
I assume you bunk frees by sitting in other classes lessons. One of My friends do that cos their Bio teachers isn't amazing


...Or they just go home in their frees at a school/college where you're not allowed to :tongue:
Original post by furryface12
...Or they just go home in their frees at a school/college where you're not allowed to :tongue:


Monday afternoons!
Original post by Felix Felicis
Let m1m_1 be Albert's mass and m2m_2 be Bella's mass and the acceleration on the lift be aa. As a force of 678N678N is exerted on Albert then 678m1g=m1a(1)678 - m_1 g = m_1 a \quad (1). Similarly, 452m2g=m2a(2)452 - m_2 g = m_2 a \quad (2).

Now, considering the lift:

3995(250+m1+m2)g=(250+m1+m2)a(3)3995 - (250 + m_1 + m_2)g = (250 + m_1 + m_2)a \quad \quad (3).

Substitute (1)(1) and (2)(2) into (3)(3).

Edit: Also, did you make a typo and should the tension in the cable of the lift be 3955 N?


I'm probably wrong, but isn't it easier to consider just the lift only for part a)? :colondollar:
Original post by L'Evil Fish
Monday afternoons!


My wednesday mornings! Although I am actually allowed atm, didn't used to be though :tongue:
Original post by furryface12
My wednesday mornings! Although I am actually allowed atm, didn't used to be though :tongue:


I get in 8am or before every day..

:mmm: used to rebel ay?
Reply 4828
Original post by adi19956
Radians/ degrees problems? This gets me sometimes


Don't know but it is annoying

Posted from TSR Mobile
Anyone think it's worth me resitting C2, C3 and M1? Alongwith FP1, S2 and M2?

Then FP2, FP3 and M3 in Year 13?

Actually, ignore that. F.Maths and Maths is all one average so I should focus on that.
(edited 10 years ago)
Original post by usycool1
I'm probably wrong, but isn't it easier to consider just the lift only for part a)? :colondollar:


I don't think you can do it that way. Could you explain your working at all?
Original post by Endless Blue
I don't think you can do it that way. Could you explain your working at all?


I shall draw you a diagram, one second :smile:
Original post by Endless Blue
I don't think you can do it that way. Could you explain your working at all?


OK, have a look at this diagram:

Lift.png

The forces that act on the lift are shown. Due to Newton's third law, the force exerted on the people by the lift is equal to the force exerted by the people on the lift, so those act on the lift downwards. The weight of the lift (250g) also acts downwards. The tension in the cable is 3955N and acts upwards. You want to find a (in orange :ahee: :tongue:)

So resolve upwards:

3955 - (250g + 678 + 452) = 250a
375 = 250a

Hence a = 1.5ms^-2 :smile:
Original post by usycool1
OK, have a look at this diagram:

Lift.png

The forces that act on the lift are shown. Due to Newton's third law, the force exerted on the people by the lift is equal to the force exerted by the people on the lift, so those act on the lift downwards. The weight of the lift (250g) also acts downwards. The tension in the cable is 3955N and acts upwards. You want to find a (in orange :ahee: :tongue:)

So resolve upwards:

3955 - (250g + 678 + 452) = 250a
375 = 250a

Hence a = 1.5ms^-2 :smile:


Makes so much more sense. Thanks, Usy! :biggrin:
Original post by Endless Blue
Makes so much more sense. Thanks, Usy! :biggrin:


No worries :hat2:
Original post by usycool1
No worries :hat2:


:facepalm: I forgot to put the g as 9.8 :mmm:

I miss mechanics, so I've vowed to be able to smash M2 before the end of half term :colonhash:
Original post by L'Evil Fish
I get in 8am or before every day..

:mmm: used to rebel ay?


It's so pointless going in when you have nothing to do and could be far more productive at home. Well sometimes it's ok, but others just a pain :rolleyes:
Original post by usycool1
No worries :hat2:


Trying not to burden you again, but does gravity act on an object moving upwards underwater? For this last question, I know the resistive force and the mass but I only have the projection speed of the object (10m/s) and I need to find the acceleration using F=ma (I think). Is there any way of calculating the resultant force with the acceleration unknown and the upwards force unknown in terms of newtons?
Original post by Endless Blue
Trying not to burden you again, but does gravity act on an object moving upwards underwater? For this last question, I know the resistive force and the mass but I only have the projection speed of the object (10m/s) and I need to find the acceleration using F=ma (I think). Is there any way of calculating the resultant force with the acceleration unknown and the upwards force unknown in terms of newtons?


It does :yep:

What's the question? :smile:
Original post by Endless Blue
Trying not to burden you again, but does gravity act on an object moving upwards underwater? For this last question, I know the resistive force and the mass but I only have the projection speed of the object (10m/s) and I need to find the acceleration using F=ma (I think). Is there any way of calculating the resultant force with the acceleration unknown and the upwards force unknown in terms of newtons?


For the question, I'd say it would. What's the full question though?

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