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

Qualification => Subject Doubts => GCE AS & A2 Level => Math => Topic started by: missbeautiful789 on March 27, 2010, 04:29:23 pm

Title: M1 question
Post by: missbeautiful789 on March 27, 2010, 04:29:23 pm

A box of weight W rests on a platform. When the platform is moving upwards with an of acceleration ?, the normal contact force from the platform on the box has magnitude kW. When the platform is moving downwards with acceleration 2?, the box remains in contact with it. find the normal contact force in terms of k and W, deduce that k ? 3/2

Title: Re: M1 question
Post by: astarmathsandphysics on March 27, 2010, 05:46:02 pm

2 hours

Title: Re: M1 question
Post by: astarmathsandphysics on March 27, 2010, 07:03:06 pm

moving up res kW-W=Wa/g (1)
moving down W=W*2a/g so a=g/2
sub into (1) kW-W=W/2 so KW=3W/2 so k=3/2