PLEASE HELP ME I DONT UNDERSTAND!!!!

A car goes from 80 km/h to 20 km/h in 0.5 h. What is the acceleration in km/h2?

Nikolay [14]

The answer is attached below.
Let me know if you don't understand it and I'll explain even more for you ☺♥

8 0

4 years ago

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If you're swimming underwater and knock two rocks together, you will hear a very loud noise. But if your friend above the water

Svetradugi [14.3K]

Answer:

The air-water interface is an example of boundary. The transmitted portion of the initial wave energy is way smaller than the reflected portion. This makes the boundary wave hard to hear.

When both the source of the sound and your ears are located underwater, the sound is louder because the sound waves can travel directly to your ear.

Explanation:

The air-to-water sound wave transmission is inhibited because more of reflection than transmission of the wave occurs at the boundary. In the end, only about 30% of the sound wave eventually reaches underwater. For sound generated underwater, all the wave energy is transmitted directly to the observer. Sound wave travel faster in water than in air because, the molecules of water are more densely packed together, and hence can easily transmit their vibration to their neighboring molecules, when compared to air.

4 0

4 years ago

Answer please. I will mark brainiest if right.

Alexandra [31]

Answer:

In this order from 1-10: F, F, F, T, T, F, F, T, T, F

Explanation:

Planets are named almost entirely from Roman gods and goddesses,

The sun is not the center of the universe, just the center of the solar system,

The solar system is believed to be formed in a gaseous nebula,

Planets and stars did form when matter clumped together with gravity,

Our solar system is believed to have 5 dwarf planets,