<h3>
Answer:</h3>
<h3>
Explanation:</h3>
_______________
h=7,5 m
g=10 m/s²
ρ=1000 kg/m³
_______________
p - ?
_______________
p=ρgh=1000 kg/m³ · 10 m/s² · 7,5 m = 75000 Pa = 75 kPa
Answer:
B. t = 0.250s
Explanation:
A. An image with the sketch of the bat emitting a sound, which reflects on a surface and return to the bat is attached below.
B. In order to calculate the time that the pulse emitted by the bat, return to the bat, you first calculate the time that pulse takes to arrive to the object.
You use the following formula:
(1)
x: distance to the object = 43m
t: time = ?
v: speed of sound beat = 343 m/s
You solve the equation (1) for t:

The time on which the bat hears the echo is twice the value of t, that is:

The time on which bat heart the echo of its sound, from the moment on which bat emitted it, is 0.250s
Good question. if it's a physical change what you would see is a change in the physical object/appearance like let's say I Tear a piece of paper, that would be a Physical change. I believe your answer would be a chemical change.