Average speed (v) = total distance(d) / total time (t)
d = 57 + 87km = 144km
t = 2 + 3hrs = 5hrs
v = d÷t = 144÷5 = 28.8km/hr
For figure one the “+” are protons and the “-“ are electrons for the second one the middle is the nucleus and the other is the orbit
Hey there! :D
We want to find an answer choice that is reversible. If the physical change could have some way of being fixed, then it is a physical change. If it is a chemical change, the make-up is different and there is no way that it could change.
A cookie baking cannot be reversed. Cookies cannot go back to being cookie dough.
Paper burning cannot be reversed. Ashes and smoke cannot go back to being paper.
However, if your ice cream melts, you can refreeze it. Therefore, "3" is the best answer to the question.
I hope this helps!
~kaikers
In order to create a magnifier in convex lens, you should choose a short focal length that is lesser than 1 meter.
<h3>What is a
convex lens?</h3>
A convex lens is also referred to as converging lens and it can be defined as a type of lens that typically causes parallel rays of light with respect to its principal axis to come to a focus (converge) and form a real image.
In Science, a magnifier refer to an optical instrument that allow us to look at a very near object because its image is generally formed farther away. Thus, the image of the object appears to be much larger.
In this context, you should choose a short focal length that is lesser than 1 meter when you want to create a magnifier in convex lens because the nearer the object is to the lens, the larger would be the image formed.
Read more on convex lens here: brainly.com/question/10153605
