There are 2 toy cars facing each other at a distance of 500 cm from each other. Each car moves forward by 100 cm at a speed of 50 cm/s and then moves backward by 50 cm at a speed of 25 cm/s. How long will it take for the cars to collide? a) 12s b) 14s c) 16s d) 13s

  • Interview Candidate
  • 22
  • 10592

Showing Answers 1 - 22 of 22 Answers

Bikash Kumar Sharma

  • Feb 23rd, 2006
 

16sec

  Was this answer useful?  Yes

Sasanka

  • Feb 26th, 2006
 

answer is 13 sec

there are 2 cars moving opposite each other with 50cm/s for 100cm in forward direction and 50cms with 25cm/sec backward direction

therefore it is enough to calculate for 1 car ie 250cms

at 2 sec car moves 100cms forward and by next 2 sec it comes backward by 50cms so total 50cms for 4sec.

for 6th sec car moves 150cms forward total and by 8th sec 100cms total.

by 10th sec car moves 200cms forward and by 12th sec 150cms total.

by 13secs car moves 250cms and collides with other car.

so ans is 13sec

  Was this answer useful?  Yes

VIJAYA BHASKAR

  • Mar 2nd, 2006
 

Upto 12th Sec 150 cm the above person wht he did is correct

From that in 2 sec it moves 100cms

so in 14 sec 250cms by single car another car also 250 cms total 500cms so both collide at 14th Sec

  Was this answer useful?  Yes

padma

  • Mar 10th, 2006
 

a------------------b

---->   500m  <----

forward direction   100cm-----50cm/s

backward direction  50cm-----25cm/s

as we know the formulae: speed=distance/time

i.e, time=distance/speed

now, for forward direction  t=100/50=2sec

for backward direction t=50/25=2sec

now since the 2 toys are travelling with equal speed, so we can guess that the 2 toys collide exactly at half the way so 500cm/2=250cm

we can directly calculate for 1 toy

at 14sec, the 2 toys collide.................

  Was this answer useful?  Yes

lalli

  • Mar 13th, 2006
 

your analysis was al correct but at the last step u made a mistake.after 12 sec its at 150 cmso after 2 more secs i.e 14 secs it reaches 250cms and collidesso the ans is 14 secs

  Was this answer useful?  Yes

sriram krishnamoorthi

  • Mar 29th, 2006
 

14 secs

        at 2 secs  each car will be moved to a dist of 100cms

        at 4 secs  each car will be moved to a dist of 50cms  

         at 6 secs  each car will be moved to a dist of 150cms

       at 8 secs  each car will be moved to a dist of 100cms

       at 10 secs  each car will be moved to a dist of 200cms

       at 12 secs  each car will be moved to a dist of 150cms

      at 14 secs  each car will be moved to a dist of 250cms that is at the point they collide

  Was this answer useful?  Yes

kanakaraj.t

  • Apr 2nd, 2006
 

Ya

That perfect answer is 14 sec..

kanagaraj

  Was this answer useful?  Yes

Raghavan

  • Dec 1st, 2006
 

Each car moves a 100 cm forward and 50 cms backwards

the total forward and a backward moment is defined as a cycle.

each cycle takes 4 seconds as 2 seconds 100 cms forward at 50 cm/s and backwards at 25 cm/s

in each cycle of 4 seconds each car moves 50 cms forwards and distance betweeen car is reduced by 100 cms

cycle 1 4 seconds

Car A moves 50 cms and same the car B

now the distance is 400 cms

cycle 2 8 seconds

Car A moves 100 cms and same the car B

now the distance is 300 cms

cycle 3 12 seconds

Car A moves 150 cms and same the car B

now the distance is 200 cms

now in the last cycle the collision occurs

as each car moves 100 cms in 2 seconds

so the 200 cms is covered by both cars

so after an instant collision, at the 12+2= 14 seconds

the car moves backwards

hence the answer is 14 seconds

raghavan iyengar

hcl technologies

  Was this answer useful?  Yes

sanjays

  • Nov 28th, 2014
 

a) 12s

  Was this answer useful?  Yes

chris

  • Nov 28th, 2014
 

b) 14s

  Was this answer useful?  Yes

roshni

  • Jan 16th, 2015
 

16s

  Was this answer useful?  Yes

Give your answer:

If you think the above answer is not correct, Please select a reason and add your answer below.

 

Related Answered Questions

 

Related Open Questions