<span>Sound waves with frequency higher that 20,000 Hz are referred to as "Ultrasonic"
Hope this helps!</span>
<span>This statement is true - humans require a certain percentage of body fat to function effectively. As a result of childbearing, women's bodies require a higher level of body fat than men: roughly 10-13%, compared to 2-5%. </span>
Based on my notes the answer must be B. horizontal layers
Answer:
It is moving from 4s to 8s at a constant speed of 4 cm/s
Explanation:
The graph would show a line with a positive gradient, this would mean that the speed would increase as more time passed. This means that it was accelerating from 0s to 4s. Thus this disproves the first option.
For the second option, we know that this is a speed time graph, so a horizontal line would symbolise constant speed. Therefore, it wouldn't be at rest and also makes the third option correct.
For the last option, the first part is correct in saying that it is 'speeding up' as we do see the speed increase due to the positive gradient. However, from the previous option (which is correct) we know that it isn't at rest and is moving at constant speed. Therefore, the last one is wrong.
And thus, the only correct option is option 3.