• Support PF! Buy your school textbooks, materials and every day products via PF Here!

Forces Problem

  • Thread starter vivekfan
  • Start date
1. The problem statement, all variables and given/known data
On takeoff, the combined action of the engines and wings exerts an 8000 N force on the plane, directed upward at an angle of 65 degrees above the horizontal. The plane rises with constant velocity in the vertical direction while continuing to accelerate in the horizontal direction. What is the weight of the plane and what is its horizontal acceleration?


2. Relevant equations

F= ma
m= w/g


3. The attempt at a solution

I'm confused because I wrote out on a free body diagram the forces in the y-direction. I put gravity, the normal force, and the y component of the force that the engine. But then I got stuck because there is no mass. The answer is just the y component of the engine force. But I don't really understand why. Once, I know the weight, then finding the horizontal acceleration is easy.
 

LowlyPion

Homework Helper
3,079
4
1. The problem statement, all variables and given/known data
On takeoff, the combined action of the engines and wings exerts an 8000 N force on the plane, directed upward at an angle of 65 degrees above the horizontal. The plane rises with constant velocity in the vertical direction while continuing to accelerate in the horizontal direction. What is the weight of the plane and what is its horizontal acceleration?

2. Relevant equations

F= ma
m= w/g

3. The attempt at a solution

I'm confused because I wrote out on a free body diagram the forces in the y-direction. I put gravity, the normal force, and the y component of the force that the engine. But then I got stuck because there is no mass. The answer is just the y component of the engine force. But I don't really understand why. Once, I know the weight, then finding the horizontal acceleration is easy.
The vertical component must be the weight of the plane. At that angle what is the vertical component of the 8000N? That's your weight.

Now you have the mass and the horizontal force, so ...
 

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving

Hot Threads

Top