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# Hardest question ever Watch

1. It's says climbing which mans going up
then why the hell is it lift equal weight

this is stooopid
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2. I can't read properly the whole thing.

From what I see it says it is climbing at "constant velocity"? The direction does not matter!

The overall forces needs to be zero to be constant (so opposite forces should be equal). If they are not equal, then there is an acceleration (F = m x a), hence, velocity increase. No matter the direction, it can even fall or go right, what is matters is the constant velocity.

When we are stand up on the ground, lift = weight, if we did not have the ground we would fall till we reach something that give an opposite and equal force to the gravity.
3. (Original post by Imrankhan0121)
It's says climbing which mans going up
then why the hell is it lift equal weight

this is stooopid
Think of Newton's laws:

An object will continue at a constant speed in a straight line of motion or will stay at rest unless acted upon by an external force.

The question says 'constant velocity' so for Newton's law to hold true, there can be NO forces acting to accelerate the aircraft.

That means all forces must be in balance hence:

thrust = drag (the aircraft cannot go faster and travels at a constant speed forwards)

lift = weight (the aircraft cannot go faster and travels at a constant speed upwards)
4. (Original post by uberteknik)
Think of Newton's laws:

An object will continue at a constant speed in a straight line of motion or will stay at rest unless acted upon by an external force.

The question says 'constant velocity' so for Newton's law to hold true, there can be NO forces acting to accelerate the aircraft.

That means all forces must be in balance hence:

thrust = drag (the aircraft cannot go faster and travels at a constant speed forwards)

lift = weight (the aircraft cannot go faster and travels at a constant speed upwards)
But it says climbing
Surely it's moving up
5. (Original post by Imrankhan0121)
But it says climbing
Surely it's moving up
Ok kind of understand with constant velocity
6. (Original post by Imrankhan0121)
Ok kind of understand with constant velocity
Exactly.

If you are sitting in a car moving forwards at a constant speed on a straight and level road, you don't feel any force because there are no forces acting to change your velocity. All of the forces acting on you are in balance.

It matters not how fast you are travelling or in which direction you are travelling as long as the car does not deviate from that straight line or changes speed.

Exactly the same thing applies to the aircraft and it does not matter the direction the aircraft is moving. As long as it maintains a constant velocity the forces acting on it are in balance.

If the car/aircraft accelerates or brakes or changes direction, it will only do so if the forces become unbalanced.

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Updated: January 10, 2015
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