The echo is heard 2.80 s later, this means this is the time the sound takes to travel to the reflecting object and then back to us. So, during this time, the sound wave has covered the distance L between us and the object twice:
The speed of the sound wave is:
, and since it is moving by uniform motion, we can find the distance covered by the wave using
And we said this corresponds to twice the distance between us and the reflecting object, so:
so, the object is 480 meters away.
Solar cells are made out of silicon wafers. These are made out of the element silicon, a hard and brittle crystalline solid that is the second most abundant element in the Earth's crust after oxygen. If you're at the beach and see shiny black specks in the sand, that's silicon.
Hope this helps!
Please give brainliest!
Explanation: Mass is Kilogram
Weight is Newton
I think its " both have level surfaces"
Answer:
When you look at a simple koi pond you can find Koi (the secondary consumer) that feeds off of the zooplankton (first consumer), they eat the phytoplankton (producers). All in a simple food chain
Explanation:
Basically, Koi eat the little animal plankton (zooplankton) that then eats the plant plankton (phytoplankton) that can only end when a part of that habitat is removed. If you got rid of the plant plankton then the whole chain would collapse and most likely die.
