A jet aircraft has an airspeed of 720 km/h and is traveling 4800 km west from Sydney to Perth. If the average wind speed is 40 km/h from the west, how long will it take the plane to reach Perth?

To find the time it will take for the plane to reach Perth, we first need to calculate the effective ground speed of the plane.

The effective ground speed is the difference between the airspeed of the plane and the wind speed. In this case, the airspeed of the plane is 720 km/h and the wind speed is 40 km/h from the west. Since the wind is coming from the west, it will slow down the plane's progress towards the west.

Effective ground speed = Airspeed - Wind speed
Effective ground speed = 720 km/h - 40 km/h
Effective ground speed = 680 km/h

Now that we have the effective ground speed of the plane, we can calculate the time it will take to travel 4800 km.

Time = Distance / Speed
Time = 4800 km / 680 km/h
Time = 7.06 hours

Therefore, it will take the plane approximately 7.06 hours to reach Perth.

Step 1: Calculate the ground speed of the plane

Ground speed = Airspeed + Wind speed (if in the same direction)
Ground speed = 720 km/h - 40 km/h = 680 km/h

Step 2: Calculate the time taken to cover the distance

Time = Distance / Ground speed
Time = 4800 km / 680 km/h

Step 3: Simplify and convert to hours

Time = 7.06 hours

Therefore, it will take the plane approximately 7.06 hours to reach Perth.