A student pushed horizontally on a book with a force of 2 N, which causes the book to slide at a constant velocity. What is the force of friction on the book?

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.

you probably know the answer. stop asking stupid questions and making me waste my time. j.k. ; )   b.t.w. what are three ratios equivalent to 5 : 11? thx

answer; silence;