Relativity Problem: Small fly inside moving vehicle -am I stupid?

[Pommie]

Maybe it's easier to see when it's not on a river,

You are walking (pick a non zero speed) on a very long moving walkway (pick any speed + or -). You drop something but don't notice for 1 minute. You turn around and walk back to the item you dropped. How long does it take to get back to the dropped item. Actually, if you think of how many paces you walk away from the item and how many to get back to it then it all becomes clear. See, simples.

Mike.

 

[mvs sarma]

perhaps not correct
there is no more drive force other than initial force for the bullet
the air resistance would slow down the bullet while the plane continues at the said speed as is driven by engines. thus your enemy would see the bullet slowing backwards., and yes it is overtaken by gravity as already pointed.

 

[killivolt]

My bullet is a mini guided, rocket propelled bullet. But, when my enemy stupidly grabs it and puts it in his pocket it explodes. Spy vs Spy

 

[ARandomOWl]

Maybe it's easier to see when it's not on a river,

You are walking (pick a non zero speed) on a very long moving walkway (pick any speed + or -). You drop something but don't notice for 1 minute. You turn around and walk back to the item you dropped. How long does it take to get back to the dropped item. Actually, if you think of how many paces you walk away from the item and how many to get back to it then it all becomes clear. See, simples.

Mike.

Ah. So it takes 15 mins for the man to collect his hat?

 

[transistor495]

I forgot to tell another fact.

The moment the enemy heard my gun firing sound, he lost the plane control and the engine stopped running..he ended up in capturing the bullet..

 

[DerStrom8]

To the people on the ground, they would see the ball moving at an angle, with a horizontal velocity equal to that of the plane (so the ball would always be directly under the plane, assuming the plane doesn't change direction or velocity), and a vertical velocity imparted by gravity.

It is not just an angle, but an arc, because gravity would be causing it to accelerate exponentially (roughly 10 meters per second, per second). Ignoring wind resistance, it will always be travelling horizontally at 1000km/h, but it's downward speed would continue to increase.

 

[DerStrom8]

Here's another case.

Suppose I'm standing on the top of a mountain and a plane just passes nearby at 1200ft/s. I see my enemy in the plane and I shoot at 1200ft/s going bullet.

The interesting thing is that the enemy can see a bullet following him at constant velocity, so that he can capture the bullet easily and put in his pocket

Post removed. I misunderstood this statement

 

[Dr_Doggy]

It is not just an angle, but an arc, because gravity would be causing it to accelerate exponentially (roughly 10 meters per second, per second). Ignoring wind resistance, it will always be travelling horizontally at 1000km/h, but it's downward speed would continue to increase.

.........unless its high enough to form an orbit.....

 

[BrownOut]

A man is in a row boat that he rows at 4kmh, he's rowing up river and the river is flowing at 1.5kmh. His hat is beside him and it blows off the boat without him noticing. He finally notices that his hat is missing after 15 minutes and immediately turns the boat around to go retrieve his hat. How long does it take for him to catch up with his hat.

And, no, this is not going off topic.

Mike.

24 minutes.

Aggh, never mind.

 

[MrAl]

A man is in a row boat that he rows at 4kmh, he's rowing up river and the river is flowing at 1.5kmh. His hat is beside him and it blows off the boat without him noticing. He finally notices that his hat is missing after 15 minutes and immediately turns the boat around to go retrieve his hat. How long does it take for him to catch up with his hat.

And, no, this is not going off topic.

Mike.

I assume by 4kmh you mean 4km/hr right? But is this measurement relative to the moving water or to the land? We need to know that to solve this.

 

[Mickster]

If he is rowing against the 1.5kmh flow at 4kmh, his progress is 2.5kmh.
If he is rowing with the 1.5kmh flow, his progress is 5.5kmh.
From the point at which his hat was lost, after 15 minutes he will be 2.5km/4 away and his hat will be 1.5km/4 in the opposite direction.
0.625km and 0.375km = 1km.
If he now rows with the flow, he will cover 1.375 km in 15 minutes, whilst his hat will have covered 0.375km in those 15 minutes....

 

[canadaelk]

Oh, come on gang. It's not about the river (what if the river stopped to have a smoke?) or some boat, it's about a fly.

The Fly!

E

 

[Pommie]

The river and the car are the same thing. Everything on the river happens regardless of the speed of the river and everything in the car happens regardless of its speed. As long as the car/river stay at a constant speed then the fly/boat/hat will behave as though the car/river is stationary. Remove the roof and the fly will get blown away.

Mike.

 

[Dr_Doggy]

all you really need to think about:

caseA(camera is at startpoint)) is if 2 things move in the opposite direction of each other one needs to have a motion of -d(distance) their velocity is the same, "from the start point".....

caseB(camera is on object B)) but the distance they gain between each other will be double that of the distance from the startpoint. thus will the velocity between EACH OTHER.......



its called relativity, because ITS RELATIVE to the PERSPECTIVE, the ball is happening all over the board, but we all see it a little differently. all graphs, maps, watever will all have a 0,0 startpoint, and thats where it starts!

 

[topquark]

You say if you open the top of the car, the insect would get smashed. Well, not true. This morning I was in a jeepney, which is not enclosed. It is open all around and at the back. In fact, our hair was flying backwards because of the wind. However, a little mosquito was flying inside the speeding jeepney, zigzagging back and forth, seemingly unaffected by the speed and the wind. I keep getting the "enclosed vehicle" and "air inside the vehicle not moving" explanations. Please someone explain this one.