Example 1

The velocity of an object fired directly upward is given by V = 80 - 32t, where t is in seconds. When will the velocity be between 32 and 64 feet per second?

Step 1. Set up the compound inequality.

Real_ex1-1

Step 2. Solve for t.

Real_ex1-2
Real_ex1-3-001

(Reminder: since the inequality is divided through by a negative,
the inequality signs need to be reversed.)

Step 3. Answer the question.

The velocity will be between 32 and 64 feet per second when the object is between 0.5 and 1.5 seconds after launch.