A couple of quickies !
1) A young couple are travelling in a bus, making its way through the mountains. They get off at their stop. A few seconds later, they watch in horror as a huge boulder rolls down the slope and hits the bus. The man looks at his companion and says ' Wish we were on that bus'. Why ?
Solution - Refer to comments.
2) A clock takes five seconds to strike five ( as in 5 oh clock ). How long does it take to strike seven ? The clock is of the old fasioned kind that makes an appearance in Indian horror movies late at night :-)
Solution - This is similar to asking another question - If you have to take 3 tablets, one every half hour , how long will it take you to have them all ? The answer is not 1.5 hours, but 1 hour. You take one right now, one after half an hour, and another one after an hour.
Similarly, when we say it takes five seconds to strike five, the time count begins at the first strike. So, the next four strikes take 5 seconds, resulting in a spacing of 1.25 ( 5/4) seconds between concecutive strikes. For seven oh clock, there are 6 such spacings, which means it should take 6*1.25 = 7.5 seconds.
Answer to question 2) 1 hour 59 mins and 55 seconds to start striking 7 + 7 seconds (assuming each strike takes 1 second). :)
ReplyDeleteA sad answer to question 1) They rode through the mountains to commit suicide. Yeah, I know it is pathetic. Or the boulder was rolling towards them after hitting the bus and the part of the bus they were sitting in was not affected?
Rafiki -
ReplyDeleteQ1 ) - Ha ha no they had no plans of committing suicide! Maybe I should add one more point here - They were the only ones to get off at their stop.
Q2)I'm sorry I should have been clearer here:-) I meant only the chime part; not the time between five, and seven. We would think the obvious answer is seven seconds but that is not correct!
So if they had not gotten down the bus would have escaped the rock. :)
ReplyDeleteok if the pendulum starts at the center and swing right and then left and comes back to the center that is 1 chime. That takes 5 seconds or basically it moves right to left 6 times. Hence at 7:00 it will swing 8 times and hence should take approximated 6.7 seconds. Right?
ReplyDeleteRafiki - Great answer to the bus question :-)
ReplyDeleteclock question - Well, that's not quite right .. We dont need to make any assumptions about the type of the pendulum swing. We can just assume it produces sound.
So what is the solution to the clock problem?
ReplyDeleteRafiki - I totally forgot about this post ! Thanks for reminding !
ReplyDelete