Two trains of 200 m and 100 m long are running parallel at the rate of 20 m/sec. and 22 m/sec. respectively. How much time will they take to cross each other, if the trains are running along the same direction? [#1132]

The difference of speed = 22m/s - 20m/s = 2m/s As the train with speed 22m/s will cross the other, hence this train have to go the smallest length of the trains distance ahead of the other to cross completely. Hence This train will be ahead of 100m with a speed of 2m/s. Hence The time to cross each other will take = 100m / (2m/s) = 50 sec

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The difference of speed = 22m/s - 20m/s = 2m/s As the train with speed 22m/s will cross the other, hence this train have to go the smallest length of the trains distance ahead of the other to cross completely. Hence This train will be ahead of 100m with a speed of 2m/s. Hence The time to cross each other will take = 100m / (2m/s) = 50 sec

A constant is a mathematical concept that represents a value that remains unchanged, like pi (π), which is approximately 3.14 and never changes.

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A constant is a mathematical concept that represents a value that remains unchanged, like pi (π), which is approximately 3.14 and never changes.

100 - 98 = 2

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100 - 98 = 2

A starts journey before B at a speed of 1 m/s. Hence A will be ahead of B (10*60)s * 1m/s = 600m Let A covers a distance of X after starting of B, Then X + 600m = 2X => 2X - X = 600m => X = 600m Hence B will cover a distance of 2X = 2 * 600m = 1200m = 1.2 km

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A starts journey before B at a speed of 1 m/s. Hence A will be ahead of B (10*60)s * 1m/s = 600m Let A covers a distance of X after starting of B, Then X + 600m = 2X => 2X - X = 600m => X = 600m Hence B will cover a distance of 2X = 2 * 600m = 1200m = 1.2 km

1

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1

Net change (-40 + 20 + $\frac{(-40)*20}{100}$)% = (-20 + $\frac{-800}{100}$)% = (-20 - 8)% = -28% = 28%

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Net change (-40 + 20 + $\frac{(-40)*20}{100}$)% = (-20 + $\frac{-800}{100}$)% = (-20 - 8)% = -28% = 28%

47

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47

4

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4

= $\sqrt{0.04} + \sqrt{1.44} + \sqrt{1.69} + \sqrt{0.0009}$ = $\sqrt{\mathrm{0.02*0.02}} + \sqrt{\mathrm{1.2*1.2}} + \sqrt{\mathrm{1.3*1.3}} + \sqrt{\mathrm{0.03*0.03}}$ = 0.2 + 1.2 + 1.3 + 0.03 = 2.73

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= $\sqrt{0.04} + \sqrt{1.44} + \sqrt{1.69} + \sqrt{0.0009}$ = $\sqrt{\mathrm{0.02*0.02}} + \sqrt{\mathrm{1.2*1.2}} + \sqrt{\mathrm{1.3*1.3}} + \sqrt{\mathrm{0.03*0.03}}$ = 0.2 + 1.2 + 1.3 + 0.03 = 2.73

Zero

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Zero