A physics book is motionless on the top of a table.?

Question

If you give it a hard push with your hand, it slides across the table then slowly comes to a stop. Use newton's first law of motion to answer the following:

A) Why does the book remain motionless before the force is applied?

B) Why does the book move when the hand pushes on it?

C) Why does the book eventually come to a stop?

D) Under what conditions would the book remain in motion at a constant speed?

Answer 1

A) Any body will move at a constant velocity unless acted upon by an unbalanced force. If something isn't moving, then its velocity is zero, and that's pretty constant. All the forces acting on the book (its weight and the normal force fromt the table) exactly cancel each other out. Therefore, the book is not being acted upon by an unbalanced force.

B) When the hand applies a force, nothing is opposing the hand. Thus, the hand acts as an unbalanced force and causes the book to accelerate. When we say accelerate, we mean change its velocity.

C) Friction is the answer to this. If the hand is removed, there is nothing to oppose friction. If the hand stayed and pushed the book for a longer period of time with just the right force, friction would be balanced and the book would move along with constant velocity.

D) Lol, I actually answered this in part C. Whatever force friction applies to stop the motion, an equal but opposite force must be applied to "balance" friction. So if friction is applying 60 N of force in one direction, a force must be applied at 60 N in the exact opposite direction.

Answer 2

(A) All objects possess inertia, which causes them to remain motionless until a force is applied.

(B) Newton's first law states that an object at rest will stay at rest, or an object in motion will stay in motion, unless acted upon by force. We push the book, causing it to start moving.

(C) See the first law. To bring the book to a halt, another force must be acting on the book. This is the friction force between the book and the table.

(D) For the book to remain in motion at a constant speed, the net force acting on it must be zero. The friction force must therefore be balanced by equal and opposite pushing force.

Answer 3

a) book is in equilibrium, that is all forces are acting equally on it so no movement can occur unless 1 is stronger then other. b) book moves due to an increase in the force that is acting on one side of the book. c) book eventually comes to a stop because of friction which acts as a retardation force. d) if the surface was smooth, ie. no friction, and there were no retardation forces present e) mass = weight x acceleration due to gravity. earths acceleration due to gravity is 9.8, therefore the weight of the book is 3/9.8 if jupiter is 10 times more then the mass is weight (3/9.8) x (10 x 9.8) so thats how you get your answer

Answer 4

A. A body at rest stays at rest unless...
B. Inertia
C. Friction and gravity.
D. In a vacuum, no gravity,