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M1 maths dynamics

Hi, I am stuck on this question:

A particle of mass 5 kg is pulled across a rough horizontal plane by a string inclined at 45o to the horizontal. The coefficient of friction between the particle and the plane is 0.6. Find the acceleration of the particle when the tension of the string is 55N?

I have resolved for the normal reaction but when I resolve along the plane I seem to get the wrong answer.

Reply 1

itsElliott

Can you send your workings / your diagram and what you have done so far? It's hard to tell you what you have done wrong without seeing what you have done so far :smile:

Reply 2

Tomgazbob

Original post by itsElliott

Can you send your workings / your diagram and what you have done so far? It's hard to tell you what you have done wrong without seeing what you have done so far :smile:

Resolving for R:

R-5gsin45=0

R=5gsin45

resolving up slope:

55-0.6R-5gcos45=5a

... but the I get wrong answer for a from this, Not sure where im going wrong? :smile:

Reply 3

gdunne42

Original post by Tomgazbob

Resolving for R:

R-5gsin45=0

R=5gsin45

resolving up slope:

55-0.6R-5gcos45=5a

... but the I get wrong answer for a from this, Not sure where im going wrong? :smile: