Answer:
The beginning time of relay race is 6.73 minutes
Step-by-step explanation:
Given as :
The final time of relay race = 3.96 minutes
Let The initial time of relay race = x minutes
At first, The time reduce by 2.1 min
So, The first time become = ( x - 2.1 ) min
At second , The time reduce by
= 0.1
So, The time become = ( x - 2.1 ) min -
min

Or, 
∵ final time of race = 3.96 min
∴
= 3.96
Or, 9 x - 21 = 3.96 × 10
Or, 9 x = 39.6 + 21
Or, 9 x = 60.6
∴ x = 
i.e x = 6.73 minutes
So, The beginning time = x = 6.73 min
Hence,The beginning time of relay race is 6.73 minutes Answer
Answer:
155 - 13 = 142 -90 = 52
Step-by-step explanation:
Answer:
Protons and neutrons each count for one AMU, and the electron counts for zero AMU. So, if the atomic mass of oxygen is 16, that means we have a total of 16 protons and neutrons. 16 total protons and neutrons minus 8 protons leaves us with 8 neutrons.
That is complicated but, I'll go with 15.
Answer:
- <em>Tangent segments from a common external point are</em> <u>congruent</u>
Explanation:
A <em>tangent</em> line to a circle is a line that touches the circle in only one point of the cirfumference, and, hence, the tangent is perpendicular to (forms a right angle with) the radius of the circle.
There are many thorems relative fo the tangent lines of a cirle.
One of those theorems states that if two tangent lines to a circle are drawn from a same external point, the two segments formed from the coomon external point to the tangency points have the same length.
Also, you must know that, from the definition, two segments of the same length are known as congruent segments.
Therefore, calling P the common external point, A one point of tangency in the circle, and B the other point of tangency, then:
- length segment PA = length segment PB.
- So, the two <u><em>tangent segments from an common enternal point are congruent.</em></u>