A block of mass 8.0 kg is placed on a rough ramp inclined at an angle of 30∘ 30^\circ\,30∘ to the horizontal, as shown in the diagram.
The coefficient of static friction between the block and the ramp is 0.40.
A force P P\,P acts on the block parallel to the ramp, directed upwards.
Calculate the minimum value of P P\,P required to prevent the block from sliding down the ramp. Give your answer to two significant figures (use g=9.8 m/s2g = 9.8\text{ m/s}^2g=9.8 m/s2).
12 N12\text{ N}12 N
39 N39\text{ N}39 N
52 N52\text{ N}52 N
66 N66\text{ N}66 N