If a ball drops on a hole and if the sound reaches up the hole In ten seconds can you find the depth of the hole. take speed of sound 400m/s and gravity 10

2125m

Explanation:

Using equation of motion

s = ut + ½at²

For motion under gravity

s = ut + ½gt²

Where u = 400m/s

g = 10m/s²

t = 10 /2 = 5s , this is because it takes double time to hear the sound just like echo

Therefore

s = ut +½gt²

s = 400×5 + ½ ×10× 5²

s = 2000 + 25×5

s = 2000 + 125

s = 2125m

The depth of the hole is 2125m or 2.125km

I hope this was helpful, please mark as brainliest

the old price per ounce is c/4.

the new price per ounce is c/3.6.

the ratio of the old price to the new one is

(c/4)/(c/3.6) = (c/c)×(3.6/4) = 0.9 . . = 9/10 . . "nine tenths" in either form

float.

archimedes' principle

denser than water sinks in water.

denser than mercury would sink in it