document.write( "Question 195768: respected sir,\r
\n" ); document.write( "\n" ); document.write( "1] A hare sees a dog 100 metres away from her,& scuds off in the opposite direction at a speed of 12 km an hour.A minute later the dog perceives her & gives chase at a speed of 16 km per hour.How soon will the dog overtake the hare ,& at what distance from the spot whence the hare took flight ?\r
\n" ); document.write( "\n" ); document.write( "2] A carriage driving in a fog passed a man who was walking at the rate of 3 km an hour in the same direction.He could see the carriage for 4 min.& it was visible to him upto a distance of 100 m. what was the speed of the carriage ?\r
\n" ); document.write( "\n" ); document.write( "plz explain me this sums...waiting for yurs reply.\r
\n" ); document.write( "\n" ); document.write( "thank u. \n" ); document.write( "

Algebra.Com's Answer #146859 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
The equations for both hare and dog are:
\n" ); document.write( " $\"d%5Bh%5D+=+r%5Bh%5D%2At%5Bh%5D\"$
\n" ); document.write( "and
\n" ); document.write( " $\"d%5Bd%5D+=+r%5Bd%5D%2At%5Bd%5D\"$
\n" ); document.write( "These are laws of constant speed motion, and
\n" ); document.write( "the key to not getting confused is to only
\n" ); document.write( "apply them when the hare and dog are moving.
\n" ); document.write( "I would like to have them both moving from
\n" ); document.write( "start to finish, but how do I do that?
\n" ); document.write( " I have a stopwatch and I will start it
\n" ); document.write( "when the dog starts running. But where is the hare
\n" ); document.write( "then? The hare has a 1 minute headstart, and
\n" ); document.write( "in that time, she goes
\n" ); document.write( " $\"d%5Bh%5D+=+12%2A%281%2F60%29\"$
\n" ); document.write( " $\"d%5Bh%5D+=+.2\"$ km
\n" ); document.write( "I start my stopwatch and stop it when the dog
\n" ); document.write( "catches the hare
\n" ); document.write( " $\"d%5Bh%5D+=+r%5Bh%5D%2At%5Bh%5D\"$
\n" ); document.write( " $\"d%5Bh%5D+=+12t%5Bh%5D\"$
\n" ); document.write( "The dog has to make up 100 m plus 200 m
\n" ); document.write( " $\"d%5Bd%5D+=+d%5Bh%5D+%2B+.3\"$ km
\n" ); document.write( " $\"d%5Bh%5D+%2B+.3+=+16%2At%5Bd%5D\"$
\n" ); document.write( "The dog's time and the hare's time will now be the
\n" ); document.write( "same on my stopwatch, so I'll say they both are $\"t\"$
\n" ); document.write( " $\"d%5Bh%5D+%2B+.3+=+16t\"$
\n" ); document.write( "(1) $\"d%5Bh%5D+=+16t+-+.3\"$
\n" ); document.write( "and
\n" ); document.write( "(2) $\"d%5Bh%5D+=+12t\"$
\n" ); document.write( "Subtract (2) from (1)
\n" ); document.write( "(1) $\"d%5Bh%5D+=+16t+-+.3\"$
\n" ); document.write( "(2) $\"-d%5Bh%5D+=+-12t\"$
\n" ); document.write( " $\"0+=+4t+-+.3\"$
\n" ); document.write( " $\"4t+=+.3\"$
\n" ); document.write( " $\"t+=+.075\"$ hr
\n" ); document.write( " $\"t+=+.075%2A60\"$ min
\n" ); document.write( " $\"t+=+4.5\"$ min
\n" ); document.write( "It takes the dog 4.5 min to overtake the hare
\n" ); document.write( "How far does the hare go in that time?
\n" ); document.write( "(1) $\"d%5Bh%5D+=+16t+-+.3\"$
\n" ); document.write( " $\"d%5Bh%5D+=+16%2A.075+-+.3\"$
\n" ); document.write( " $\"d%5Bh%5D+=+1.2+-+.3\"$
\n" ); document.write( " $\"d%5Bh%5D+=+.9\"$ km
\n" ); document.write( "But the hare is already 200 m from her starting point, so
\n" ); document.write( "The dog overtakes the hare at
\n" ); document.write( " $\".9+%2B+.2+=+1.1\"$ km
\n" ); document.write( "1100 m from the hare's starting point
\n" ); document.write( "check answer:
\n" ); document.write( "The dog has to go
\n" ); document.write( " $\".1+%2B+1.1+=+1.2\"$ km in .075 hr to catch the hare
\n" ); document.write( " $\"d%5Bd%5D+=+16%2At\"$
\n" ); document.write( " $\"1.2+=+16%2A.075\"$
\n" ); document.write( " $\"1.2+=+1.2\"$
\n" ); document.write( "OK
\n" ); document.write( "I don't have time for the other question, sorry\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

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