# Thread: M1 question- Resolving frictional forces

1. ## M1 question- Resolving frictional forces

Hi

I am having a problem with this question, and was wondering whether I could have a bit of a nudge in the correct direction?

I cannot do part 'iv'; however, I think that I may have worked out part iv for question iii though Im not sure

The answers I have so far are:

A) i)

Resolve horizontally- $80*cos 25 = 72.5N$

ii)

Fmax= Coefficient of friction x R:

$Fmax= 0.32*80 = 25.6N$

iii)

Mass= $80/9.8= 8.16kg$

-> $T + 8.16*cos 25 = 80*sin 25$

$T= 80*sin 25 - 8.16*cos 25 = 26.14N$

v)

$80/9.8= 8.16kg$

Any help is greately appreciated concerning parts iii and iv

2. Originally Posted by fishkeeper
Hi

I am having a problem with this question, and was wondering whether I could have a bit of a nudge in the correct direction?

I cannot do part 'iv'; however, I think that I may have worked out part iv for question iii though Im not sure

The answers I have so far are:

A) i)

Resolve horizontally- $80*cos 25 = 72.5N$

ii)

Fmax= Coefficient of friction x R:

$Fmax= 0.32*80 = 25.6N$

iii)

Mass= $80/9.8= 8.16kg$

-> $T + 8.16*cos 25 = 80*sin 25$

$T= 80*sin 25 - 8.16*cos 25 = 26.14N$

v)

$80/9.8= 8.16kg$

Any help is greately appreciated concerning parts iii and iv

iii) $T_{min} = mg\sin{\theta} - f_{s \, max}$

iv) $T_{max} = mg\sin{\theta} + f_{s \, max}$

3. thankyou Skeeter

That helps enourmously!