Question

4. Draw free body diagrams for the situations below.
velocity of 5 m/s
a. A book is moving on a frictionless table top at a constant velocity.
b. A spider hangs motionless from a thread of silk.​

Answer 1

Answer:

See the diagrams in attachment

Explanation:

a) We are told that the book is moving at a constant velocity. This means that its acceleration is zero: therefore, since the table is frictionless (no friction), there are no forces acting along the horizontal direction.

Along the vertical direction, the book is in equilibrium as well, so there are 2 forces equal and opposite that balance each other, and they are:

- The weight of the book, downward, labelled with W

- The normal reaction of the table on the book, upward, labelled with N

b) Here there is no motion along the horizontal direction - so no forces at all along this direction.

Along the vertical direction, the spider is hanging motionless: this means that its acceleration is zero, so the net force must be zero. Again, this means that there are 2 forces equal and opposite that balance each other, and they are:

- The weight of the spider, downward, labelled with W

- The tension in the thread of silk, upward, labelled with T