Author Topic: All Mechanics DOUBTS HERE!!!  (Read 85144 times)

Offline astarmathsandphysics

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Re: All Mechanics DOUBTS HERE!!!
« Reply #135 on: May 22, 2010, 12:02:13 am »
1st thing in morning

Offline falafail

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Re: All Mechanics DOUBTS HERE!!!
« Reply #136 on: May 22, 2010, 12:03:41 am »
Someone help me with january 2009 Q7 (b)..

I have the mark scheme i just don't understand how they freakn get there =/

CIE or edexcel?

Offline Saladin

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Re: All Mechanics DOUBTS HERE!!!
« Reply #137 on: May 22, 2010, 07:28:59 am »
Answering it soon.

Offline Sweet_03

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Re: All Mechanics DOUBTS HERE!!!
« Reply #138 on: May 22, 2010, 07:41:51 am »
hello

M1 , jan2006
can someone please explain how to do :
all of Question 4
and Question 6 part (d) only
 :-[


Offline Saladin

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Re: All Mechanics DOUBTS HERE!!!
« Reply #139 on: May 22, 2010, 08:19:59 am »
Answering it soon.

Jan 2009 m1

7(b)

This is basically asking you to find the resistance force that R give Q. The thing thatprevents it from having an acceleration of 9.8 ms-2

So

5g-N=5a

5*9.8-5*5.88=N

N=19.6

Offline halosh92

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Re: All Mechanics DOUBTS HERE!!!
« Reply #140 on: May 22, 2010, 09:15:28 am »
M1 edexcel
jan 2001
Q6d
URGENT! thx
everyday we wake up is a miracle, then how do we say miracles dont happen?????

Offline Saladin

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Re: All Mechanics DOUBTS HERE!!!
« Reply #141 on: May 22, 2010, 09:24:28 am »
M1 edexcel
jan 2001
Q6d
URGENT! thx

Post all your working upto 6 (c)

or else i will have to do the whole thing

Offline halosh92

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Re: All Mechanics DOUBTS HERE!!!
« Reply #142 on: May 22, 2010, 09:54:50 am »
Post all your working upto 6 (c)

or else i will have to do the whole thing

sure

b) v=u +at
v=at
v = 9.8 *2 = 19.6 m/s

c) 1/2 * 2 *19.6 = 19.6m
1/2 * (19.6 + 4) *5 = 59
59 + 19.6= 78.6m

everyday we wake up is a miracle, then how do we say miracles dont happen?????

Offline astarmathsandphysics

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Re: All Mechanics DOUBTS HERE!!!
« Reply #143 on: May 22, 2010, 11:31:46 am »
here

Offline halosh92

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Re: All Mechanics DOUBTS HERE!!!
« Reply #144 on: May 22, 2010, 12:01:02 pm »
sure

b) v=u +at
v=at
v = 9.8 *2 = 19.6 m/s

c) 1/2 * 2 *19.6 = 19.6m
1/2 * (19.6 + 4) *5 = 59
59 + 19.6= 78.6m



could someone solve this plz :(
everyday we wake up is a miracle, then how do we say miracles dont happen?????

Offline Phosu

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Re: All Mechanics DOUBTS HERE!!!
« Reply #145 on: May 22, 2010, 12:31:53 pm »
the distance that the helicopter is above the ground is 125m
this is the total distance under the graph, since its the total distance that the woman covers before reaching the ground
out of which 78.6m is the distance between the woman in air, and the helicopter

125=78.6+4T
4T=46.4
T=11.6

total time taken = 2+5+11.6=18.6s

Offline Ghost Of Highbury

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Re: All Mechanics DOUBTS HERE!!!
« Reply #146 on: May 22, 2010, 12:38:31 pm »
A load of weight 7kN is being raised from the rest with constant acceleration by a cable. After the load has been raised 20 metres, the cable suddenly becomes slack. The load continues to move upwards for a distance of 4 metres before coming to an instantaneous rest. Assume no air resistance, find the tension in the cable before it became slack.
divine intervention!

Offline halosh92

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Re: All Mechanics DOUBTS HERE!!!
« Reply #147 on: May 22, 2010, 12:47:09 pm »
the distance that the helicopter is above the ground is 125m
this is the total distance under the graph, since its the total distance that the woman covers before reaching the ground
out of which 78.6m is the distance between the woman in air, and the helicopter

125=78.6+4T
4T=46.4
T=11.6

total time taken = 2+5+11.6=18.6s


how did u get this equation exactly??
everyday we wake up is a miracle, then how do we say miracles dont happen?????

Offline Phosu

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Re: All Mechanics DOUBTS HERE!!!
« Reply #148 on: May 22, 2010, 12:57:41 pm »
how did u get this equation exactly??

which one?
the calculation of T or the total time taken?

Offline halosh92

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Re: All Mechanics DOUBTS HERE!!!
« Reply #149 on: May 22, 2010, 01:07:52 pm »
which one?
the calculation of T or the total time taken?

no calculation for T
everyday we wake up is a miracle, then how do we say miracles dont happen?????