Will the helicopter take off?

[her209]

The helicopter is placed on a large turntable. The rotor is place directly over the center of the turn table. The turn table is spun in one direction as fast as necessary.

Case 1: The helicopter rotor is not turned on.

Case 2: The helicopter rotor is turned on but rotates counter to the turntable. The speed of the turn table matches the speed of rotor in the opposite direction.

In which case(s) does the helicopter take off or does it not take off at all and why?

 

[zoiks]

42.

 

[minendo]

Originally posted by: her209
The helicopter is placed on a large turntable. The rotor is place directly over the center of the turn table. The turn table is spun in one direction as fast as necessary.

Case 1: The helicopter rotor is not turned on.

Case 2: The helicopter rotor is turned on but rotates counter to the turntable. The speed of the turn table matches the speed of rotor in the opposite direction.

In which case(s) does the helicopter take off or does it not take off at all and why?

Neither because the pilot failed to show up.

 

[Vich]

Originally posted by: her209
The helicopter is placed on a large turntable. The rotor is place directly over the center of the turn table. The turn table is spun in one direction as fast as necessary.

Case 1: The helicopter rotor is not turned on.

Case 2: The helicopter rotor is turned on but rotates counter to the turntable. The speed of the turn table matches the speed of rotor in the opposite direction.

In which case(s) does the helicopter take off or does it not take off at all and why?

Is the turn-table playing any sort of Light FM music? If so then no.

 

[Kev]

Originally posted by: her209
The helicopter is placed on a large turntable. The rotor is place directly over the center of the turn table. The turn table is spun in one direction as fast as necessary.

Case 1: The helicopter rotor is not turned on.

Case 2: The helicopter rotor is turned on but rotates counter to the turntable. The speed of the turn table matches the speed of rotor in the opposite direction.

In which case(s) does the helicopter take off or does it not take off at all and why?

Case 2: wouldn't you want the rotor rotating in the same direction as the turntable for the purposes of your brain teaser? Because the way you have it, i t's pretty obvious that it would take off

 

[Kalvin00]

this is retarded

 

[MichaelD]

I refuse to do your damn homework for you. Get a damn graphing calculator and do it yourself!

That's what I would say if I was math-smart and could actually even fathom how to solve that equation. My math knowledge is limited to "X+2=5" and questions of similar difficulty.

Problems like yours and the "infamous algebra word problem" have always made me want to jump in front of a freight train.

Two trains leave two different stations on opposite sides of the world at random times of the 24 hour clock. John has two apples. Mary's temperature is 32.123 Kelvin degrees. If the train goes backwards until it's wheels reach a temperature of 423C, how many oranges will John's brother, Steve have at exactly 13:45GMT?

/head explodes

 

[CaptnKirk]

A helicopter blade is an airfoil, and an airfoil moving through the air provides lift.

Case# 1 - If the rotational speed of the entire machine reached a sufficient velocity to allow the blades
to develop enough lift to overcome the weight of the machine, it will take off, and then prompty crash back down
as aerodynamic friction reduces the capability of the blades to provide and sustain lift.

It's like the helicopter on a stick toy you can get in the stores


Case# 2 - no blade rotation, no lift = stationary, a static machine.

 

[Murphy Durphy]

I've actually seen this in a math teaser book.

I'm going to B&N today, maybe I'll take a peak at the answer (which shouldn't be too hard to figure out) but more importantly the explanation.

 

[SlitheryDee]

Originally posted by: CaptnKirk
A helicopter blade is an airfoil, and an airfoil moving through the air provides lift.

Case# 1 - If the rotational speed of the entire machine reached a sufficient velocity to allow the blades
to develop enough lift to overcome the weight of the machine, it will take off, and then prompty crash back down
as aerodynamic friction reduces the capability of the blades to provide and sustain lift.

It's like the helicopter on a stick toy you can get in the stores


Case# 2 - no blade rotation, no lift = stationary, a static machine.

HAHA No 1200 reply thread for you OP. :laugh:

 

[yosuke188]

Wouldn't the centrifugal force push the helicopter off the turn table? I don't know much about physics, but I don't think it can just spin and stay still.

 

[ta8689]

The Helicopter isnt balanced to spin like a top. Plus.... you do know that there is a vertically mounted rotor in the back to control spinning, so if there was a pilot in the helicopter.... he would just counter the spinning with that, or at least enough to let the thing come off the spinning table. you know.. this is a truely retarded post.

 

[destrekor]

Originally posted by: MichaelD

Two trains leave two different stations on opposite sides of the world at random times of the 24 hour clock. John has two apples. Mary's temperature is 32.123 Kelvin degrees. If the train goes backwards until it's wheels reach a temperature of 423C, how many oranges will John's brother, Steve have at exactly 13:45GMT?

LMAO

 

[her209]

Originally posted by: Kev
Case 2: wouldn't you want the rotor rotating in the same direction as the turntable for the purposes of your brain teaser? Because the way you have it, i t's pretty obvious that it would take off

Wouldn't rotating the turn table in the same direction just add to the rotation speed of the rotor? Kind of like when you're in a car, if you throw a ball forward, wouldn't the ball's velocity = to the speed you're traveling + velocity of the ball after it has been accelerated by your arm.

I can see what you're talking about though. If the rotor spins while the helicopter is on still ground, its the same as holding the rotor still and the bottom portion rotating in the opposite direction. So it would seem that by rotating the bottom portion helicopter, you are just speeding up the speed of rotor.

 

[slayer202]

Originally posted by: MichaelD

Two trains leave two different stations on opposite sides of the world at random times of the 24 hour clock. John has two apples. Mary's temperature is 32.123 Kelvin degrees. If the train goes backwards until it's wheels reach a temperature of 423C, how many oranges will John's brother, Steve have at exactly 13:45GMT?

/head explodes

that's nothing. try doing that problem assuming you are in a vacuum

 

[Whoozyerdaddy]

The pilot will vomit and pass out before the helo has a chance to do anything.