I've done part i)Quote:

A block B of mass 0.4 kg and a particle P of mass 0.3 kg are connected by a light inextensible string. The string passes over a smooth pulley at the edge of a rough horizontal table. B is in contact with the table and the part of the string between B and the pulley is horizontal. P hangs freely below the pulley (see diagram).

Code:`(i) The systemis in limiting equilibrium with the string taut and P on the point of moving downwards.`

Find the coefficient of friction between B and the table. [5]

Code:`(ii) A horizontal force of magnitude X N, acting directly away from the pulley, is now applied to B.`

The system is again in limiting equilibrium with the string taut, and with P now on the point of moving upwards. Find the value of X.

3 (i) T = 0.3g

F = T

R = 0.4g

F = μR

Coefficient is 0.75

but how do i do part 2?

I got W=T for P

so 0.3g=T

For B: T-F-X=0

0.3g-0.3g-X=0

wouldnt X=0?

but the answer states it's

X = 0.3g + 0.3g

X = 5.88N

thanks for your help!