There are four dogs/ants/people at four corners of a square
of unit distance. At the same instant all of them start
running with unit speed towards the person on their
clockwise direction and will always run towards that target.
How long does it take for them to meet and where?

Answer Posted / venkat

answer # 3 is almost correct. they will meet at the center however the time they would take according to my calculation is not 1 unit of time but less than 1 unit of time [approx 0.78 unit of time]. the reason being since all of the four are moving tracing arcs toward the center of the square, the distance of the arc is definitely less than 1 unit [little more than half the diagonal distance, half the diagonal distance is about = 0.707 unit]. the question says speed and not velocity. speed is distance traversed / time taken to cover the distance. Here distance is the length of the arc [0.78 unit] to be precise and not even half the diagonal distance [0.70 unit], leave alone the initial distance [1 unit] between the two people. arc length that I got was using this formula: (2 x pi x 0.5) / 4 = 0.78. Further 1 unit speed = 0.78 unit / time and it follows time = 0.78 unit of time.

Is This Answer Correct ?    1 Yes 2 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Radha,Geeta&Revathi went for a picnic.After a few days they forgot the date,day and month on which they went to picnic.Radha said that it was on Thursday,May 8 and Geeta said that it was Thursday May 10.Revathi said Friday Jun 8.Now one of them told all things wrongly,others one thing wrong and the last two things wrongly.If April 1st is tuesday what is the right day,date and month?

894


Radha, Geeta & Revathi went for a picnic.After a few days they forgot the date,day and month on which they went to picnic.Radha said that it was on Thursday,May 8 and Geeta said that it was Thursday May 10.Revathi said Friday June 8.Now one of them told all things wrongly,others one thing wrong and the last two things wrongly.If April 1st is tuesday what is the right day,date and month?

772


George while driving along the highway saw road markers which are at equal distances from each other. He crosses the markers every 20 seconds. If he increases his speed by x meters per second, he crosses the markers at every 15 seconds. But if he increases his speed by y meters per second, he crosses the marker at every 10th second. If y-x = 40 meters per second, then what is the distance between two markers.

915


two persons run a race of 100m. the winner won by (110/11)m and one second in time. find the speed of lsoer in met

726


Perimeter of the back whell = 9 feet, front wheel = 7 feet on a certain distance the front wheel gets 10 revolutions more than back wheel . what is the distance?

862






vernanlar : place :: finger print : ?

686


Find the unit digit of product of the prime number up to 50 ?

993


Suhana gets 70% in Maths, 80% in Physics. To get an overall of 75% how much should she get in English.

721


A man has 2 cows of total cost 200 rupees. He sold them for 210. For 1 cow he had a profit of 10% and for the other he had a loss of 10%. What is the price of each cow?

932


There are three types of tickets available for a concert: orchestra , which cost $12 each; balcony, which cost$9 each: and box, which cost $25 each. There were P orchestra tickets , B balcony tickets, and R box tickets sold for the concert. Which of the following expressions gives the percentage of ticket proceeds due to the sale of orchestra tickets?

1192


sir i need rrb secunderabad goodsguard previous exam papers

1800


A beats B by 10 meters and B beats C by 15 meters the A beats C by

712


Age of Grandfather is the ages of 4 grandchildren where their ages are in consecutive.Find the age of Grandfather.

992


two workers can type two pages in two minuets then how many persons can type 18 pages in 6 minuets

1002


Two trains are traveling at 18kmph and are 60 km apart. There is flying in the train. It flies at 80kmph. It flies and hits the second train and then it starts to oscillate between the two trains. At one instance when the two trains colloide it dies. At what distance travel by the fly.

892