Two balls A and B placed at the top of 180m tall tower. Ball A is from the top at t = 0s. Ball B is thrown vertically down with an initial velocity ‘u’ at t = 2s. After a certain time, both balls meet 100m above the ground. Find the value of ‘u’ in ms-1.
[use g = 10 ms-2] :
Two balls A and B placed at the top of 180m tall tower. Ball A is from the top at t = 0s. Ball B is thrown vertically down with an initial velocity ‘u’ at t = 2s. After a certain time, both balls meet 100m above the ground. Find the value of ‘u’ in ms-1.
[use g = 10 ms-2] :
Option 1 -
10
Option 2 -
15
Option 3 -
20
Option 4 -
30
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1 Answer
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Correct Option - 4
Detailed Solution:Let 't' be the time taken by B to meat A.
for A, u = 0
t = [2 + t]
h = 80m
a = 10 m/sec2
h = ut +
80 = 0 * t +
t + 2 = 4
t = 2sec
Now for B
h = ut +
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Similar Questions for you
Let ‘t’ be the time taken by B to meat

A.
for A, u = 0
t = [2 + t]
h = 80m
a = 10 m/sec2
h = ut +
80 = 0 × t +
16 = (2 + t)2
t + 2 = 4
t = 2sec
Now for B
h = ut +
80 = 2u + 5 × 2 × 2
80 = 2u + 20
2u = 60
u = 30m/sec
h = 39.2 + 19.6 = 58.8 m
Height above tower
= 19.6
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