Forces

Practice

practice problem 1

Draw a free body diagram of …
  1. a book lying on a level table.
  2. a person floating in still water.
  3. a wrecking ball hanging vertically from a cable.
  4. a helicopter hovering in place.

solution

In all four cases, the downward pull of gravity is balanced by an upward force. There are no significant lateral (side-to-side) forces in these examples. Read the discussion section of this topic for a more detailed explanation.

a. a book b. a person c. a wrecking ball d. a helicopter

practice problem 2

Draw a free body diagram of a child pushing a wagon on level ground.

solution

The solution to this problem depends on the direction of the acceleration of the wagon. Read the discussion section of this topic for a more detailed explanation.



a child pushing a wagon on level ground

practice problem 3

Write something different.

solution

Answer it.

practice problem 4

Write something completely different.

solution

Answer it.

The Physics Hypertextbook

  • No condition is permanent.