Question

A plane flies at 190 mph for the first and last half hour of a flight. It flies at a higher constant speed for the rest of the flight. The route is 2090 miles. The plane is 990 miles from the destination 2 hours before the end of the flight.How many hours is the entire flight?

Answer 1

Answer:

4.18 hours

Step-by-step explanation:

Since the plane needs 2 hours to cover the las 990 miles at the end of the flight, and in the last half hour it flies with a speed of 190mph, meaning it covers a distance of 190 / 2 = 95 miles in this last half hours.

That means for the other 1.5 hours, its cruising speed is

$v_c = \frac{990 - 95}{1.5} = 596.7 mph$

Beside the first and last half hour of the trip (which covers 190 miles), the cruising distance must be

d = 2090 - 190 = 1900 miles

The cruising time is therefore

$t_c = \frac{d}{v_c} = \frac{1900}{596.7} = 3.18 hours$

Hence the total time for the entire flight is

3.18 + 1 = 4.18 hours

Answer 2

In 4.18 hours is the entire flight.

Given

A plane flies at 190 mph for the first and last half hours of a flight.

It flies at a higher constant speed for the rest of the flight.

The route is 2090 miles.

The plane is 990 miles from the destination 2 hours before the end of the flight.

Speed;

The plane needs 2 hours to cover the last 990 miles at the end of the flight, and in the last half hour it flies with a speed of 190mph,

Then,

The distance covered by plane in last half hour is;

$\rm Distance=\dfrac{190}{2}\\\\Distance=95 \ miles$

The velocity is;

$\rm Velocity = \dfrac{Distance }{Time}\\\\Velocity=\dfrac{900-95}{1.5}\\\\Velocity=\dfrac{805}{1.5}\\\\Velocity=596.7$

The first and last half hour of the trip (which covers 190 miles), the cruising distance must be;

Distance = 2090 - 190 = 1900 miles

Therefore,

The cruising time is;

$\rm Time =\dfrac{Distance}{Velocity}\\\\Time=\dfrac{1900}{596.7}\\\\Time=3.18 \ hours$

The total time for the entire flight is

= 3.18 + 1 = 4.18 hours

Hence, in 4.18 hours is the entire flight.

To know more about distance click the link given below.

https://brainly.com/question/23345050