How Much Work Does a Plane's Engine Perform to Reach 3200m at 65m/s?

In summary, the problem involves a 1500 kg plane that starts at rest and reaches an elevation of 3200 m while traveling at a speed of 65 m/s. The question asks for the minimum work done by the plane's engine in this time, disregarding air resistance. The relevant equations for solving this problem are work equals force times distance and force equals mass times acceleration. However, these equations are insufficient and the concept of conservation of energy must be applied. The sum of the change in kinetic energy and the change in potential energy equals the correct answer of 5.0 x 10^7. This is because the kinetic energy on the ground is converted to potential energy at 3200m and the kinetic energy
  • #1
Some_Thing
5
0

Homework Statement



A 1500 kg plane, initially at rest, leaves an airfield and a short time later it is at an elevation of 3200 m traveling at 65 m/s. What is the minimum work done by the plane's engine in this time? (Ignore air resistance)


Homework Equations



W=Fd, F=ma, and most certainly some other ones.


The Attempt at a Solution



This is what I understand from the question:

Vox = 0 m/s

Voy = 0 m/s

dy = 3200 m

m = 1500 kg

I assume that at 3200m, the plane starts to fly only horizontally, so "65 m/s" would be Vfx.


The problem is that this seems insufficient for any of the kinematics formulas, and I don't see how I could use it in different areas (like dynamics).


What am I missing here? Can someone please give me a push in the right direction?

Any help is greatly appreciated,

Thanks.
 
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  • #2
Kinematic equations won't do you any good here. Can you tell me which quantity is conserved in this system?
 
  • #3
Cyosis said:
Kinematic equations won't do you any good here. Can you tell me which quantity is conserved in this system?

Ah, I see, its one of those conservation of energy questions, isn't it?

Change in Ek + Change in Ep = the correct answer (5.0 x 10^7)

Thanks!


One thing bugs me though. Shouldn't these two add up to 0?
 
  • #4
Some_Thing said:
Ah, I see, its one of those conservation of energy questions, isn't it?

Change in Ek + Change in Ep = the correct answer (5.0 x 10^7)

Thanks!


One thing bugs me though. Shouldn't these two add up to 0?

Why would they add up to zero?

There is no potential energy on the ground. The change in kinetic energy on the ground is converted to potential energy at 3200m in the air and kinetic energy to make it travel at 65m/s
 

FAQ: How Much Work Does a Plane's Engine Perform to Reach 3200m at 65m/s?

What is "Work done by Air Plane"?

"Work done by Air Plane" refers to the amount of energy expended by an airplane in order to overcome resistance and move through the air. It is typically measured in joules or kilojoules.

How is the work done by an airplane calculated?

The work done by an airplane is calculated by multiplying the force of air resistance, also known as drag, by the distance traveled. This formula can be expressed as W = F x d, where W is work, F is force, and d is distance.

What factors affect the work done by an airplane?

The work done by an airplane is affected by several factors, including the speed and weight of the aircraft, the density of the air, and the shape and design of the airplane's wings and body. Air temperature and altitude can also impact the amount of work done by an airplane.

Why is the work done by an airplane important?

The work done by an airplane is important because it determines the amount of fuel and energy required for the aircraft to travel a certain distance. This information is crucial for pilots and engineers to plan flights and optimize fuel efficiency.

Can the work done by an airplane be negative?

Yes, the work done by an airplane can be negative if the force of drag is greater than the force propelling the aircraft forward. This can happen in situations such as strong headwinds or during descent. In these cases, the airplane is expending energy to slow down or maintain its speed, resulting in a negative work value.

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