Since the other answer got deleted, i'll just answer it for you.
a sinoatrial node is the main pacemaker that begins each heartbeat located in the junctions of superior vena cava and the right atrium. It signals from the node that spread through the atria and determines the heart rates.
Answer:
I think it's c (if y is chloroplasts)
Answer:
Explanation:
Yes, for a couple of reasons.
1. Carbon connects easily with other carbons.
2. Carbon forms chemical that can change and connect with other carbons even in biology or especially in Biology. If you take a brown seen and plant it where it can get water and soil nutrients, to will come up as a green plant. Think about the chemistry that goes into that. Not only that, but there are mechanisms that tell the upper part of the plant that the roots can't supply any more growth. Isn't that something? All made from Carbon.
3. The human body is a mass of Carbon based chemicals and all cells there can have different functions. Amazing isn't it? I'm a fan of the diversity of our planet and its growth.
Explanation:
I wrote out an explanation but it said "Rude! We don't use such words here. Please change it". I honestly don't know what word i couldn't use but I just could not post it. I tried changing any words that may have caused it but it did not fix the issue. So here are the answers only.
A. 12.5 m/s.
The average speed is defined as the relationship between the displacement made by a body and the total time it took to perform it.
The formula that will allow you to calculate the average speed is:
v = d/t, where d is the traveled distance and t the time it took to travel the distance.
We hace to convert 4 minutes to second:
(60 s/1 min)*(4 min) = 240 s
So, the average speed is:
v = 3000 m/240 s
v = 12.5 m/s