Question
A meter-long pipe is made whose internal diameter is
equal to the outer radius. How much material (cubic units) will be required to make the pipe if it holds 88/7m³?Solution
Let the radius of the inner cylinder be r and the radius of the outer cylinder be R. 2r = RÂ In this figure, the amount of water that will flow will be equal to the volume of the inner cylinder.
The volume of cylinder = Ï€r2h 88/7 = 22/7 ×1× r2 r = 2 , then R = 4 Materials used to make pipe (volume) = volume of outer cylinder - volume of the inner cylinder = Ï€R2h-Ï€r²h V = Ï€h (R2 -r2 ) V = 22/7 ×1×(16-4) V = 22/7 ×1×12 V = 37.7 m³Â
Train 'C' running with a speed of 90 km/hr crosses a pole in 8 seconds. In how much time will train 'C' cross train 'D' whose length is 80 meters more a...
- Train 'A' having a speed of 20 m/s can cross a man in 5 seconds. The length of train 'B' is 100 metres more than the length of 'A'. If the speed of 'B' is ...
A train that is 360 metres long passes a signal post in 18 seconds. How long will it take to pass a bridge that is 240 metres long?
Two poles are positioned at a certain distance from each other. A train traveling at a speed of 90 km/hr passes the first pole in 5 seconds and reaches ...
A train moving at a speed of 72 km/h takes 12.5 seconds to pass a pole. If the train takes 24 seconds to completely cross a platform, what is the lengt...
A train crosses a bridge in 15 secs while it crosses a man standing on a platform in 8 secs. If the speed of train 108 km/hrs, then what will be the ti...
- A train, running at the speed of 72 km/h, is 300 metres long. How much time (in seconds) will it take to pass over a bridge that is 600 metres long?
- A train can cross a bridge and a pole in 7.2 seconds and 4 seconds respectively. The length of the bridge is 80 metres. Find the time taken by train to cro...
Two trains A and B, were proceeding in the same direction on parallel tracks at 24 km/hr and 78 km/hr respectively. A man noticed that it took exactly 2...
Train ‘X’ is travelling with a speed of 90 km/hr and crosses a vertical pole in 6 seconds. Train ‘Y’ is 30 metres longer than ‘X’ and trave...