Answer:
If Earth suddenly lost all of its gravity, we wouldn't just start floating. ... That's because the planet would continue spinning, without exerting gravity to keep objects tied to it [source: Domanico]. A loss of gravity would also mean that the planet would stop pulling down air, water and Earth's atmosphere.
Answer:
Electromagnetic waves do not require a medium in order to transport their energy. Mechanical waves are waves that require a medium in order to transport their energy from one location to another. ... Sound is a mechanical wave and cannot travel through a vacuum.
Time = Distance / speed
Time = 2.5 km / 23 km/h
= 0.1087 hours 1 hour = 60 minutes
= 0.1087 * 60 minutes
= 6.522 minutes.
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