Question

In the below figure, a horizontal force ? ⃗
? of magnitude 20.0 ? is applied to a 3.0 ?? psychology book as
the book slides up a distance ? = 0.500 ? on frictionless ramp at angle ? = 30°.
A. What is the net work done on the book? (4 marks)
B. If the book has zero kinetic energy at the start of the displacement, what is its speed at the end of the
displacement? (2 marks)

Answer 1

A. Fisse F mg cosa mgsino a 30° ing Moss of the book, m= 3.0kg Applied force fa= 20.00 from the figure, we have fnet = fa cosa mgano - 20 cos 300 - 3.0x9.8 Sin 30° - 17.32 - 14.7 Fnet = 2.62 N Net work done on the book fret x d 2.62 X 0.500 W 1:31 J B. From work- energy theorem, change in Kinetic work done energy KA Ki =

kt end of the final kinetic energy {mva speed of book at the displacement initial Kinetic energy =o (given) พ & mv²= 2. W v 2X1.31 3 ay 2 v 0.93 m/s