The Burning Field

[Blueboy]

Yet another one:

Two boys are playing football outside a field of wheat which 12 foot high walls surrounding it. The boys each stand 5 feet tall. One of the boys kicks the ball over the wall, into the field. Both boys then run through a door into the field to retrieve it.

Once inside they discover 2 things. The door can only be open from the outside, there is no handle on the inside of the door, so it cannot be reopened. Also, to the north of the field, there is a fire burning steadily in a line from east to west. The fire is slowly travelling southwards, towards them.

The field is 100 ft by 100 ft. There is now no way out of the field, no way of jumping over the fire or quenching it.

Within half an hour the fire will reach them, if they do nothing, they will be burnt alive.

How can they save themselves from this fire?

[B00]

ginormous plowter ;-)

[stewey]

As an aside, I think that both of these hot-headed little fire-ball football players should be charged with trespassing , ingressing one-way doors, crop stomping, arson, and utter befuddlement . I bet they were also wearing blazers?

[mjd]

They run towards the fire and pick some wheat which they twist into a torch which they light from the fire. Then they run south to say 25 ft from the wall and light the wheat in a line from east to west. They follow this line of fire until it reaches the wall where it burns out. The original fire stops at the point where they lit the second one

[Dustybun]

what happens if the wind changes direction though?

[rccatnap]

When the fire burns the wheat it travels towards the boys. Behind the line of fire is burnt wheat but no fire. If they run very fast through the fire, they should be able to make it to the other side of the flames, scorched a bit, but safe.

[Physics_Singer]

The kids should grab some wheat and light it as the fire reaches the northern end of the enclosure.  They can then move halfway toward the southern end and light the wheat along an east west line.  They should then wait in the center of the enclosure.  As the fire approaches them from the north, they'll be forming a safe (i.e. already burned, so no longer burnable) zone toward the south that they be able to retreat into as the fire eventually reaches them from the north.