Physics, asked by Mahirakhan13, 1 year ago

A pebble is dropped freely in a well from its top it takes 20sec for the pebble to reach water surface. g=10m/s square and speed of sound 330m/s. Find depth of the water surface. The time when eco is heard after pebble is dropped.

Answers

Answered by rahulranjanbhusari
4

Answer:

time = 20 sec

g = 10 m/sec square

u = 0 m/sec square

s = ut + 1/2gt square

s = 0 + 1/2 × 10 ×20 ×20

s= 2000 meter

speed of sound =330 m/sec

time taken = 2000/330. sec

time taken =6.06 sec

time taken to hear eco = 20 +6.06 =26.06

Answered by AbhinavRag
1
Time 20s
g is 10 m/s^2
Speed of sound 330 m/s
Initial velocity(u)=0

Using displacement(s)= ut + 1/2gt^2
0(20) + 1/2 (10)(20)^

By solving its
1/2 (500)
=250m

Therefore depth of well is 250 m


Now
Time when echo is heard
=time taken for stone to reach well surface + time taken for echo to come back

=20s + depth of well / speed of sound

=20s + 250 / 330
Which is ALMOST 20.75s
Thank you
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