Plane direction and veloctiy question

In summary, the conversation is about determining the ground velocity of a light plane traveling at 175km/h with a 40km/h wind from N80[degrees]East. After calculating the plane's velocity relative to the air and the air's velocity relative to the ground, the total ground velocity is found to be (180.14,63.7). However, the magnitude of the velocity is incorrect and should be 167 km/h. The speaker is unsure of what they are doing wrong and requests help in fixing the error.
  • #1
mathzing
9
0
alright, here is the question and how far i got.

A light plane is traveling at 175km/h on a heading of N8[degree]E in a 40km/h wind from N80[degrees]East. Determine the planes ground velocity

im going to skip the notations so..

planes velocity relative to the air is (175cos8, 175sin8)
= (173.2,24.3)

air velocity relative to the ground is (40cos80, 40sin80)
= (6.94,39.4)

you add both and get (180.14,63.7)

and the magnitude which is the velocity of the plance relative to the air is 191.07km/h

191.07km/h is wrong, it should be 167 km/h.

I don't understand what i am doing wrong.
Yes, i do know how to find the direction, but if the speed is wrong there is no point in trying to find the direction becuase it too would be wrong. any ideas on how to fix?
 
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  • #2
Draw your vectors, it will be more easy to determine what you're doing wrong.
 
  • #3


As a scientist, it is important to always double check your calculations and equations to ensure accuracy. In this case, it seems like there may have been a mistake in the way the air velocity was calculated. The correct values for the air velocity relative to the ground should be (40cos10, 40sin10) = (38.7,6.94). When you add this to the plane's velocity relative to the air, you should get a ground velocity of (212.0,31.2) which has a magnitude of approximately 215 km/h. This is closer to the expected value of 167 km/h, but it is still slightly off. It is possible that there may be other factors at play, such as air resistance or changes in wind speed and direction. It would be helpful to double check the given information and equations, and also consider any other factors that may affect the plane's ground velocity.
 

FAQ: Plane direction and veloctiy question

1) What is the difference between plane direction and velocity?

Plane direction refers to the heading or orientation of a plane in relation to a reference point, such as a compass direction. Velocity, on the other hand, is the rate of change of an object's position over time, and it includes both speed and direction.

2) How is plane direction and velocity measured?

Plane direction can be measured using a compass or other navigational instruments. Velocity can be measured using radar, GPS, or calculating the change in position over a specific time interval.

3) How does wind affect a plane's direction and velocity?

Wind can significantly affect a plane's direction and velocity. If the wind is blowing in the same direction as the plane, it can increase its velocity. However, if the wind is blowing in the opposite direction, it can decrease the plane's velocity and even cause it to change direction.

4) How does a pilot control a plane's direction and velocity?

Pilots use a combination of control surfaces such as the rudder, ailerons, and elevators to control a plane's direction and velocity. These surfaces help to adjust the airflow around the plane and change its orientation in the air.

5) Can a plane change direction and velocity while in flight?

Yes, a plane can change its direction and velocity while in flight. Pilots use the control surfaces and adjust the engine power to change the plane's direction and velocity as needed, depending on factors such as wind, weather, and air traffic control instructions.

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