Question

An airplane descends during the last hour of its flight to prepare for landing. Its altitude changes at an average of -0.15 km per minute for those 60 minutes. What is the total change in altitude of the airplane during this time?

1) 9 km
2) -9 km
3) 0.15 km
4) -0.15 km

Answer 1

The total change in altitude for the airplane descending at -0.15 km per minute for an hour is -9 km.

Step-by-step explanation:

The student asked about the total change in altitude of an airplane which descends at an average of -0.15 km per minute for 60 minutes. To calculate the total change, we multiply the rate of altitude change per minute by the number of minutes. The calculation is as follows:

• -0.15 km/min × 60 min = -9 km

The negative sign indicates that the airplane is descending, so the correct answer is choice 2) -9 km, which is the total change in altitude.