Question

A student slides a book across a desk, with a velocity of +8 m/s. When her friend catches the book, it has a velocity of +7.4 m/s. If the acceleration was a constant -5.6 m/s2, how wide is the desk?

Answer 1

kinematic equation

v^2=u^2+2*a*s

7.4^2=8^2-2*5.6^2*width

(7.4^2-64)/(2*5.6^2)=-width