# Calculate Airplane Speed: How Fast Does It Go?

## Question:

If an airplane flies in a straight line between two cities that are separated by 840 kilometers and the trip takes 4 hours, what is its speed?

## Answer:

To calculate the speed of the airplane, we can use the formula speed = distance / time. In this case, the distance is 840 kilometers and the time is 4 hours. Therefore, the speed of the airplane is 840 km / 4 hours = 210 km/hr.

## Explanation:

When determining the speed of an object such as an airplane, we need to consider the distance it travels and the time it takes to cover that distance. In this scenario, the airplane travels a distance of 840 kilometers between the two cities. The time taken for the trip is 4 hours.

By dividing the total distance by the time taken, we can find the speed of the airplane. Therefore, 840 km divided by 4 hours gives us a speed of 210 km/hr. This means that the airplane is moving at a speed of 210 kilometers per hour during its journey between the two cities.

Understanding the speed of an airplane is important for various reasons, such as estimating travel time, fuel consumption, and overall efficiency of the flight. By calculating the speed accurately, airlines can optimize their flight schedules and operations to ensure smooth and timely travel for passengers.