A falling stone accelerates at a constant rate of 10ms^2. It is dropped from rest down a deep well and 3s later a splash is heard as it hits the water below.(1) How fast will it be moving as it hits the water? (2)What will be its average speed over the three seconds ? (3) how deep is the well ?

Answer 1

find the speed of sound. If it is x m/s, then you have two equal distances.

The distance fallen is s = 5t^2, so the falling time is √(s/5)

The sound takes s/x seconds to come back.

√(s/5) + s/x = 3

So, look up x and do the math for s, the well depth.

The rest then come easily...

Answer 2

I don't. know

Answer 3

Dereje

Answer 4

Oct 27, 2015

Answer 5

Teacher

Answer 6

1) 30m/s
2) 15m/s
3) 45m