An Absurd Problem For You About A Fly Between Two Trains

Since each train is travelling at 20 miles per hour and they have 2 miles between them this means that if they travel 1 mile each, they'll meet each other. It would take 3 minutes for an object travelling at 20 miles per hour and since the fly is travelling at 60 miles per hour it would cover 3 miles in 3 minutes.

Applying the concept of relative velocity,

Relative velocity of one train with respect to the other = (20 + 20)mph = 40 mph

Distance between the trains = 2 miles

Time in which the trains will collide = 2 miles / 40 mph = 1/20 hr

Given that speed of the fly = 60 mph

So in the time 1/20 hr, the fly would fly a distance = 60 mph x 1/20 hr = 3 miles

as two trains are at 20mph, with a distance 2miles in btw, each would travel 1mile before collision......

thus, they take 1/20 hr to collide...

at 1/20 hr time, the fly flying at 60 mph would travel

1/20*60=3 miles

The Original Version

Both Trains together will cover total 2 miles and relative speed is 20 +20=40mph then TIME: 2/40=1/20 hr. Time: 1/20 hr. and speed of fly:60mph distance:1/20.60 =3 Miles

it's logically easy, the fly flies towards a train, it flies 3/4 of the distance while the train cuts the 1/4 till they meet, then when we do this respectively calculating the other train's cut distance, we'll have first distance the fly cuts is 1.5 Miles, then 0.75 miles, then 0.375 miles and so on, when we sum it all up in total miles, we get 3 miles ^^

Applying the concept of relative velocity,

Relative velocity of one train with respect to the other = (20 + 20)mph = 40 mph

Distance between the trains = 2 miles

Time in which the trains will collide = 2 miles / 40 mph = 1/20 hr

Given that speed of the fly = 60 mph

So in the time 1/20 hr, the fly would fly a distance = 60 mph x 1/20 hr = 3 miles

Actually you can solve this problem easily without calculus.Time taken for the 2 trains to meet=time taken for the fly to be squashed.The trains will meet after 2 miles/(20mph+20mph)=1/20 hour.Then use 1/20 hour x 60mph=3 miles, and it is done.

the fly will travel untill trains will reaches at each other. let trains will take time t to do so' by kinematics, s=ut ,where s=2 and relative velocity of the trains is 40. now we find that t=1/20 the distance travelled by fly is D=ut,where u=60,t=1/20 on putting u and t, we that D=3miles

V1 + V2 = 20 + 20 = 40 Mph Time × Speed = Distance X × 40 = 2 , Time = 0/05 h 0/05 × 60 = 3 Mile

The two trains have a combined speed of 40 mph. It will take them $\frac{2}{40}$ or $\frac{1}{20}$ of an hour to meet (travel two miles). If the fly is going at 60 mph then it will travel 60 $\times$ $\frac{1}{20}$ or $\frac{60}{20}$ miles, which can be simplified to 3 miles.

TRAINS MOVE WITH SAME SPEED WILL MEET AT HALF OF DISTANCE B/W THEM= 2/2= 1MILE TIME TO COVER DISTANCE 1 MILE AT THE SPEED OF 20 MPH= 60X60X1/20=180 SECONDS (T=S/V) DISTANCE COVERED IN 180 SECONDS AT SPEED OF 60 MPH= 60X180/60X60= 3 MILES (S=VXT)

as Trains are approaching each other their effective speed will be double of each (40 mph) how much time will those trains take to cover 2 miles will be( s=vt ) 3 minutes now speed of fly is 60mph how much it will cover in 3 minutes is (s=vt) 3 miles

distance = 2 miles = 3218 meters

the speed of the train = 20 m/h

they will meet within 80.45 hours

 t=d/v

 t= (3218 m) / (2)(20 m/h)

 t= (3218 m) / (40 m/h)

 t= 80.45 h

the speed of the super fly (obviously faster than the trains) = 60 m/h

thus within the same amount of time, it would travel 3 miles

 d=vt

 d=(60 m/h)(80.45 h)

 d=4827 m

 d= 2.99936 miles or equivalently 3 miles

First of all we use the beautiful fact that Time is the 4th dimension. the two trains basically approach each other at a speed of (20+20)=40mph. so, time taken for the trains to meet =1/40 *2= 1/20 hours. speed of the fly being 60mph.. we simply multiply its speed with the time interval calculated =60 * 1/20 =3miles!

The relative velocity of the two trains is 20 - (-20) = 40 mph and that means the collision will occur in 2/40 = 1/20 hrs.

The fly moving at a constant 60 mph in this time will cover a distance of 60 x (1/20) = 3 miles!

PS: One hell of a fly this fellow ;)

Since both the trains are moving with equal speeds, they will hit at 1 mile from either end. Now we can find the time taken to crash by the formula speed=distance/time. Time will come out to be 0.05 hours.

Now, dist. = speed x time (speed=60mph given and time = 0.05hrs) So, dist = 60x0.05=3 miles

It takes the trains (\frac{2}{20+20} = \frac{1}{20} ) of an hour for the trains to meet.Because the fly flies at 60 mph,the distance the fly travels before it is squashed is $\frac{1}{20} \times 60 miles = 3 miles$ .

Suppose the fly take t sec to reach train A from the initial point...

So, Train A travels= 20 t distance and so do Train B and the fly has covered 60 t distance The Difference between train now becomes =2miles-(2 20 t)

And this process continues till the train collides or the separation between both the trains becomes 0

2-(2 20 dt)=0

t=1/20 and fly covers 60*t distance

If we consider the time taken for both events, that is the trains travelling towards each other and the fly going back and forth it should be the same .

Time taken for the train to collide=distance/relative speed=2/(20+20)=1/20 hours

Thus this is the time for which the fly is going back and forth.

Distance covered by the fly = speed x time = 60 x 1/20= 3 miles

The trains will collide in 3 minutes. At the speed it flies, it will fly that number of miles, 3.

You can also use absurd summations, but I wouldn't recommend it.

Because 2 trains are travelling at 20 mph and they are 2 miles apart, so each takes 1 mile to the impact.

Using t=\frac{s}{v} gives 0.01h to the impact. This is just a time that makes the fly squashed

Using s=v \times t gives us the answer is 3

Trains travel at 20mph from each side, so they have to travel 1 mile each to collide. Time taken for them to travel 1 mile is 3 minutes. The fly can fly for 3 minutes, at 60mph, he would have travelled 3 miles.