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A ball is dropped from a bridge of 122.5m above a river.after the ball has been falling for 2sec.a second ball is thrown straigjt down after it.initial velocity of second ball so that both hits the water at same time is?
Most Upvoted Answer
A ball is dropped from a bridge of 122.5m above a river.after the ball...
Solution:
Given, height of the bridge, h = 122.5 m and time for which the first ball falls, t = 2 s.
Let the initial velocity of the second ball be u.
Calculating the time of flight of the first ball:
We know that the distance travelled by an object falling freely under gravity is given by:
s = ut + 1/2 gt²
Here, u = initial velocity = 0 (since the ball is dropped from rest)
g = acceleration due to gravity = 9.8 m/s²
t = time of flight of the first ball = 2 s
s = height of the bridge = h = 122.5 m
Substituting the values, we get:
h = 1/2 gt²
122.5 = 1/2 × 9.8 × 2²
Therefore, the time of flight of the first ball is:
t = sqrt(122.5/4.9) = sqrt(25) = 5 s
Calculating the distance travelled by the second ball:
The distance travelled by the second ball is also given by:
s = ut + 1/2 gt²
Here, u = initial velocity of the second ball
g = acceleration due to gravity = 9.8 m/s²
t = time of flight of the second ball = 5 - 2 = 3 s (since the second ball is thrown 2 s after the first ball is dropped and both hit the water at the same time)
s = height of the bridge = h = 122.5 m
Substituting the values, we get:
122.5 = ut + 1/2 × 9.8 × 3²
122.5 = ut + 44.1
ut = 122.5 - 44.1 = 78.4
Therefore, the initial velocity of the second ball is:
u = ut/t = 78.4/3 = 26.13 m/s (approx)
Hence, the initial velocity of the second ball should be 26.13 m/s (approx) so that both balls hit the water at the same time.
Given, height of the bridge, h = 122.5 m and time for which the first ball falls, t = 2 s.
Let the initial velocity of the second ball be u.
Calculating the time of flight of the first ball:
We know that the distance travelled by an object falling freely under gravity is given by:
s = ut + 1/2 gt²
Here, u = initial velocity = 0 (since the ball is dropped from rest)
g = acceleration due to gravity = 9.8 m/s²
t = time of flight of the first ball = 2 s
s = height of the bridge = h = 122.5 m
Substituting the values, we get:
h = 1/2 gt²
122.5 = 1/2 × 9.8 × 2²
Therefore, the time of flight of the first ball is:
t = sqrt(122.5/4.9) = sqrt(25) = 5 s
Calculating the distance travelled by the second ball:
The distance travelled by the second ball is also given by:
s = ut + 1/2 gt²
Here, u = initial velocity of the second ball
g = acceleration due to gravity = 9.8 m/s²
t = time of flight of the second ball = 5 - 2 = 3 s (since the second ball is thrown 2 s after the first ball is dropped and both hit the water at the same time)
s = height of the bridge = h = 122.5 m
Substituting the values, we get:
122.5 = ut + 1/2 × 9.8 × 3²
122.5 = ut + 44.1
ut = 122.5 - 44.1 = 78.4
Therefore, the initial velocity of the second ball is:
u = ut/t = 78.4/3 = 26.13 m/s (approx)
Hence, the initial velocity of the second ball should be 26.13 m/s (approx) so that both balls hit the water at the same time.
Community Answer
A ball is dropped from a bridge of 122.5m above a river.after the ball...
Answer:
26.133 m/s
Explanation:
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
26.133 m/s
Explanation:
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
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A ball is dropped from a bridge of 122.5m above a river.after the ball has been falling for 2sec.a second ball is thrown straigjt down after it.initial velocity of second ball so that both hits the water at same time is?
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A ball is dropped from a bridge of 122.5m above a river.after the ball has been falling for 2sec.a second ball is thrown straigjt down after it.initial velocity of second ball so that both hits the water at same time is? for Class 11 2024 is part of Class 11 preparation. The Question and answers have been prepared according to the Class 11 exam syllabus. Information about A ball is dropped from a bridge of 122.5m above a river.after the ball has been falling for 2sec.a second ball is thrown straigjt down after it.initial velocity of second ball so that both hits the water at same time is? covers all topics & solutions for Class 11 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A ball is dropped from a bridge of 122.5m above a river.after the ball has been falling for 2sec.a second ball is thrown straigjt down after it.initial velocity of second ball so that both hits the water at same time is?.
A ball is dropped from a bridge of 122.5m above a river.after the ball has been falling for 2sec.a second ball is thrown straigjt down after it.initial velocity of second ball so that both hits the water at same time is? for Class 11 2024 is part of Class 11 preparation. The Question and answers have been prepared according to the Class 11 exam syllabus. Information about A ball is dropped from a bridge of 122.5m above a river.after the ball has been falling for 2sec.a second ball is thrown straigjt down after it.initial velocity of second ball so that both hits the water at same time is? covers all topics & solutions for Class 11 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A ball is dropped from a bridge of 122.5m above a river.after the ball has been falling for 2sec.a second ball is thrown straigjt down after it.initial velocity of second ball so that both hits the water at same time is?.
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