The coefficient of kinetic friction between the block and the surface after point B is approximately 0.30. Hence the correct option is c.
As the block moves down the frictionless curve from point A to point B, its kinetic energy is converted into potential energy. After passing point B, a friction force acts against the motion, causing the block to decelerate and eventually come to a stop. The work done by friction is equal to the initial kinetic energy of the block.
Using the work-energy principle, we can equate the work done by friction to the change in kinetic energy. The formula for work done by friction is W friction=μk⋅m⋅g⋅d is the coefficient of kinetic friction, m is the mass of the block, g is the acceleration due to gravity, and d is the distance traveled after point B.
The change in kinetic energy is given by ΔKE= 1/2 mv^2, where v is the final velocity of the block after coming to a stop.
Setting these two expressions equal and solving for the coefficient of kinetic friction (μk), we find μk ≈0.30. Therefore, the correct answer is option C, indicating that the coefficient of kinetic friction between the block and the surface after point B is approximately 0.30. Hence the correct option is c.