A block A of mass 1\,kg rests on a block B of mass 4\,kg. The coefficient of static friction between A and B is 0.50. The floor is perfectly smooth. A horizontal force F is applied to B. What is the largest value of F for which A does not slide over B? (Take g = 9.8\,m\,s−2.)
a) 29.4N
b) 24.5N
c) 19.6N
d) 25N