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TSD Boat part - 2
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Boat part - 2

Bharat Gupta is teaching live on Unacademy Plus

Bharat Gupta
Engineer by degree Mathematician by Heart. Having 22 years of teaching experience. Visit my youtube channel BHARAT GUPTA-RADIX .

U
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sir can you please expalain how time taken by the wooden block is 2.5 hrs in the second question ? i did not understand the logic...please explain ..thank you for the effort !!
SONGS
3 months ago
1.5 hr downstream and 1hour upstream
Another method- for 3rd question, ratio of speed will be the ratio of distance travelled in equal time, therefore boat travel 80mwhile hat travelled 20m so speed are in ratio S ⛵/S🎓 4/1 . And speed of stream is 1/4 that is 25% of the boat 's speed in Still water.
SONGS
3 months ago
but bro speed of ⛵ is different for upstream and downstream means we don't have constant speed
SONGS
3 months ago
I was thinking the same but that's wrong approch
in last ques we can say time taken by man to cover 80 m (30+30+20) at speed X km\h is equal to time taken to cover 20 m by hat at (X*r/100) speed of km/h. so final equation is (80/X)=((20*100)/(X*r)) where r equal to 25 so 25%
sir in 1st question when rakesh is going to siddharth that time (as before he was downstream)but then he turned, hence his motion will be against the stream now
sir I was able to solve all the 4 questions but I take too much time your way of teaching is very good thank you sir
  1. TIME, SPEED AND DISTANCE Boat 2


  2. Rakesh and Siddharth row on a river simultaneously from the same point. Rakesh rows downstream and Siddharth rows upstream. In 15 min, they are 2.25 km apart. Rakesh then turns to follow Siddharth and after 30 min from the beginning, the boats have rowed together 3.5 km, if the speed of Rakesh, Siddharth and stream are constant at how many km/hr stream flows? c. 5 d. 2.5 (Question by Satyajit) A boat while going downstream, passes a floating wooden block. After 1.5 hr, the boat reaches bank of river and immediately turns back. After moving for 1 hour, the boat crosses that wooden piece again at a point which is 10 km ahead of the place where it was found earlier. Find the speed of stream in km/hr. 4 b. 3 d. 2.5 A man rowing upstream in a river accidently dropped his hat into the river. After travelling a distance of 30 m, he noticed it and immediately turned back to search for it. He found his hat after it had covered a distance of 20 m. If the speed of stream was r percent of the speed at which he rows in still eater, find value of r a. 20 b. 30 c. 25 d. 12.5


  3. Rakesh and Siddharth row on a river simultaneously from the same point. Rakesh rows downstream and Siddharth rows upstream. In 15 min, they are 2.25 km apart. Rakesh then turns to follow Siddharth and after 30 min from the beginning, the boats have rowed together 3.5 km, if the speed of Rakesh, Siddharth and stream are constant at how many km/hr stream flows . 3 s?: (Question by Satyajit) b. 2 c. 5 d. 2.5


  4. Rakesh and Siddharth row on a river simultaneously from the same point. Rakesh rows downstream and Siddharth rows upstream. In 15 min, they are 2.25 km apart. Rakesh then turns to follow Siddharth and after 30 min from the beginning, the boats have rowed together 3.5 km, if the speed of Rakesh, Siddharth and stream are constant at how many km/hr stream flows?: Question by Satyapt) (37) 4


  5. A boat while going downstream, passes a floating wooden block. After 1.5 hr, the boat reaches bank of river and immediately turns back. After moving for 1 hour, the boat crosses that wooden piece again at a point which is 10 km ahead of the place where it was found earlier. Find the speed of stream in km/hr a. 4 b. 3 c. 5 d. 2.5


  6. A boat while going downstream, passes a floating wooden block. After 1.5 hr, the boat reaches bank of river and immediately turns back. After moving for 1 hour, the boat crosses that wooden piece again at a point which is 10 km ahead of the place where it was found earlier. Find the speed of stream in km/hr a. 4 b. 3 C. d. 2.5 av


  7. A man rowing upstream in a river accidently dropped his hat into the river. After travelling a distance of 30 m, he noticed it and immediately turned back to search for it. He found his hat after it had covered a distance of 20 m. If the speed of stream was r percent of the speed at which he rows in still eater, find value of r: a.20 b, 30 c. 25 d' 12.5


  8. A man rowing upstream in a river accidently dropped his hat into the river. After travelling a distance of 30 m, he noticed it and immediately turned back to search for it. He found his hat after it had covered a distance of 20 m. If the speed of stream was r percent of the speed at which he rows in still eater, find value of r: a.20 b.30 c. 25 d' 12.5 244


  9. A man rowing upstream in a river accidently dropped his hat into the river. After travelling a distance of 30 m, he noticed it and immediately turned back to search for it. He found his hat after it had covered a distance of 20 m. If the speed of stream was r percent of the speed at which he rows in still eater, find value of r: a.20 b, 30 c. 25 d' 12.5 lo lo 1.