What Is the Takeoff Speed of an Aircraft Based on a Watch's Angle?

  • Thread starter Thread starter fuzzy
  • Start date Start date
  • Tags Tags
    Forces
AI Thread Summary
The discussion revolves around estimating the takeoff speed of an aircraft based on the angle of a watch held by a passenger during takeoff. The watch makes a 25° angle with the vertical, leading to the calculation of acceleration using the tangent function, resulting in an acceleration of approximately 4.57 m/s². By applying the formula for velocity, the estimated takeoff speed is calculated to be around 82.2 m/s. This speed translates to approximately 300 km/h, which aligns with realistic takeoff speeds for jetliners. The calculations and conclusions presented confirm the accuracy of the estimated takeoff speed.
fuzzy
Messages
6
Reaction score
0
Francesca dangles her watch from a thin piece of string while the jetliner she is in takes off from JFK Airport. She notices that the string makes an angle of 25° with respect to the vertical while the aircraft accelerates for takeoff, which takes about 18s. Estimate the takeoff speed of the aircraft.

k so you know that the force of gravity is mg and it's going down, and that the acceleration is ma along the horizontal, and so can you take the tan(25)=a/9.8 to get an acceleration of 4.57m/s^2?

And so for velocity you would get V=Vo+at
V=0+(4.57)(18)
V=82.2m/s?

thanks for reading
 
Last edited:
Physics news on Phys.org
It seems to be correct. Which means the take-off speed is around 300 km/h which is realistic.
 
Last edited:
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

Solving a Physics Problem with Jetliner Takeoff Speed - Casey's Story
Replies
9
Views
2K
Estimate takeoff speed of aircraft
Replies
8
Views
7K
Using an angle and time to find Acceleration
Replies
6
Views
9K
Problem: Watch attached to a string in an airplane
Replies
4
Views
16K
Tension of an object hanging in an airplane
Replies
2
Views
6K
New to forum and having major problems with couple problems
Replies
4
Views
8K
Solving Boat's Friction Force and Speed
Replies
9
Views
2K
Vectors. Calculating Weight (N) of Plane with force and angle of take off
Replies
1
Views
3K
How Does an Accelerometer Help Calculate Plane Takeoff Speed?
Replies
2
Views
4K
What is the largest pulling force before the string breaks?
Replies
13
Views
5K

Hot Threads

Recent Insights

Back
Top