Grade 11Mechanics

A ball is dropped from a bridge of 122.5 metres above a river . After the ball has been falling for two seconds, a second ball is thrown straight down after it. Initial velocity of second ball so that both hit the water at the same time is

Soumyadeep

11 Years agoGrade 11

3 Answers

Hasan Naqvi

11 Years ago

time taken by first ball to hit water can be found as

s= ut + ½ gt²

122.5 = ½ * 9.8 * t²

t²= 25

t =5

Now the next ball must cover this distance in 3 s to hit water at same time.

122.5 = 3 u + ½ * 9.8 * 3²

122.5 = 3u + 44.1

3u = 78.4

u= 26.133 m/s

Adarsh Anand

10 Years ago

time taken by first ball to hit water can be found as

s= ut + ½ gt2

122.5 = ½ * 9.8 * t2

t2= 25

t =5

Now the next ball must cover this distance in 3 s to hit water at same time.

122.5 = 3 u + ½ * 9.8 * 32

122.5 = 3u + 44.1

3u = 78.4

u= 26.133 m/s

Kushagra Madhukar

5 Years ago

Dear student,

Please find the solution to your problem.

Time taken by first ball to hit water can be found as

s= ut + ½ gt²

122.5 = ½ * 9.8 * t²

t²= 25

t =5

Now the next ball must cover this distance in 3 s to hit water at same time.

122.5 = 3 u + ½ * 9.8 * 3²

122.5 = 3u + 44.1

3u = 78.4

u= 26.133 m/s

Thanks and regards,

Kushagra

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A ball is dropped from a bridge of 122.5 metres above a river . After the ball has been falling for two seconds, a second ball is thrown straight down after it. Initial velocity of second ball so that both hit the water at the same time is

Soumyadeep

3 Answers

Hasan Naqvi

Adarsh Anand

Kushagra Madhukar

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