9. A ball with a weight of m ~ N(20, 0.1²) kg is placed between the 45° grooves A and B of the 25° incline. Determine the probability that the external force P ~ N(9, 0.05²) N which is independent from m may hold the ball up from slipping if the coefficient of friction between the ball and groove is .

Answer:

The probability that the external force P can hold the ball is 99.66%.