# 1)a small coin is dropped down a well.the splash is heard 2.3s later.how deep is the well?I(assuming sound travels quickly enough for any delaying effect to be ignored)2)a stone is thrown upwards from the top of a tower 85m high.it reaches the ground in 5 seconds.calculate1)the greatest height above the ground.2)the velocity with which it reaches the ground.3)time taken to reach maximum height(g=10ms^2)3)a stone falls freely under gravity,starting from rest.calculate the ratio of distance,travelled by the stone during the first half of any interval of time to the distance travelled during the second half of the same interval   • 1

2 ka 1) 37.5
first find the initial velocity through  ( v=u+at)
put v as 0 because when the stone is at the top it comes to rest thats why put it 0

- v=u+at
0=u + (9.8)5
0=u + 49
-49=u

then to find the greatest height use ( v2-u2=2as) [ 2 is square that no. ]

v2-u2=2as

02-(-49)2=2(9.8)s

0+2401=19.6s

2401 / 19.6 =s

122.5 =s
so the greatest height  =122.5
i m not sure that my ans is correct plzz check it and let me know too :)

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Actually when i tried this question i too got the same answer as you,but the answer given is 88.2m.I dont know whether theres any mistake in the answer given but anyways thankyou!

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