IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: nid404 on October 16, 2009, 08:35:35 am

Title: mechanics...help!!!!!
Post by: nid404 on October 16, 2009, 08:35:35 am
A car comes to a stop from 30m/s in a distance of 804m. The driver brakes so as to produce a deceleration of 1/2 m/s2 to begin with, and then brakes harder to produce a deceleration of 3/2 m/s2. Find the speed of the car at the instant when the deceleration is increased, and the total time the car takes to stop


HELP!!!
Title: Re: mechanics...help!!!!!
Post by: astarmathsandphysics on October 16, 2009, 10:38:42 am
At the and it shoulb be8+36=44 second to stop
Title: Re: mechanics...help!!!!!
Post by: nid404 on October 16, 2009, 10:44:27 am
 ;D thanks
Title: Re: mechanics...help!!!!!
Post by: mousa on October 16, 2009, 04:10:46 pm
Quote from: astarmathsandphysics on October 16, 2009, 10:38:42 am
At the and it shoulb be8+36=44 second to stop

Thanks alot astar!!
Title: Re: mechanics...help!!!!!
Post by: sanity_master on October 18, 2009, 10:38:50 am
wanted to make a new topic...but if this is still working then i shall post my request here.....


would someone plz post the formulas that r in our syllabus nd we need to use in the exam??

cuz i just noticed that i missed some of them during my study.......so i just need the list

anyone?? :)
Title: Re: mechanics...help!!!!!
Post by: nid404 on October 18, 2009, 11:18:35 am
Quote from: sanity_master on October 18, 2009, 10:38:50 am
wanted to make a new topic...but if this is still working then i shall post my request here.....


would someone plz post the formulas that r in our syllabus nd we need to use in the exam??

cuz i just noticed that i missed some of them during my study.......so i just need the list

anyone?? :)

check the pure math syllabus
Title: Re: mechanics...help!!!!!
Post by: astarmathsandphysics on October 18, 2009, 11:20:47 am
I will do it. I posted a formula sheet on my website. I will add to it.
Title: Re: mechanics...help!!!!!
Post by: sanity_master on October 18, 2009, 11:35:47 am
Quote from: nid404 on October 18, 2009, 11:18:35 am
check the pure math syllabus

y didnt i think of that? :D LOL

i totally forgot about it.....Thanks :D

nd Thanks astar
Title: Re: mechanics...help!!!!!
Post by: sanity_master on October 18, 2009, 11:46:47 am
didnt find wt i need in the syllabus......:(

i guess the formulas i missed were related to........when two objects starts moving but maybe from different positions......or same positions......i saw it at somebody's notebook........it was like....

SA = SB + X

and

SA = SB

something like that.......i dont remember them very well, so i just needed the list of needed formulas to knw them
Title: Re: mechanics...help!!!!!
Post by: sanity_master on October 18, 2009, 12:32:10 pm
guys....i knew wt i am lookin for....its the overtake part in the kinematics.

would some1 plz.....explain it to me......cuz i totally missed that part.

Thanks in advance.
Title: Re: mechanics...help!!!!!
Post by: astarmathsandphysics on October 18, 2009, 01:39:36 pm
Somhing link this?
http://www.astarmathsandphysics.com/igcse_maths_notes/igcse_maths_notes_relative_velocities_and_relative_positions.html
Title: Re: mechanics...help!!!!!
Post by: sanity_master on October 18, 2009, 03:29:19 pm
its not that one.....but its has the same idea......Thanks astar :D

nd guys.....forget about my request, i guess i got the idea......thank u all :)
Title: Re: mechanics...help!!!!!
Post by: preity on October 19, 2009, 06:07:50 am
can someone explain wat does equilibrium means in mechanics?
Title: Re: mechanics...help!!!!!
Post by: nid404 on October 19, 2009, 07:17:26 am
Quote from: preity on October 19, 2009, 06:07:50 am
can someone explain wat does equilibrium means in mechanics?

it means there is no resultant force acting on the body....the body is stable

When a body is in a state of equilibrium, the clockwise moment is equal to the anticlockwise moment and the sum of vectors in all directions is zero.(or there is no resultant vector)