It's been a while since I've studied this, but my answers would be:
13. 5730 years. The half-life of a substance is the amount of time it takes for half of it to decay, and, according to the graph, half of the substance remained at 5730 years.
14. 10740 years. According to the graph, only 25% of the carbon remained after 10740 years.
15. 15 atoms. According to the graph, only 12.5% of the carbon remained after 16110 years. 12.5% of 120 atoms is 15 atoms.
16. 1600 atoms. According to the graph, if a sample of carbon is 10740 years old, only 25% of it remains. To find the original amount, multiply the current amount by (100% / 25%), which equals 4. So, 4. 400 atoms * 4 = 1600 atoms is the original amount.
The property of matter that is responsible for electrical phenomena, existing in a positive or negative form.
.................yes...................
The distance travel is 69.5 meters.
<u>Explanation:</u>
Given datas are as follows
Speed = 27.8 meters / second
Time = 2.5 seconds
The formula to calculate the speed using distance and time is
Speed = Distance ÷ Time (units)
Then Distance = Speed × Time (units)
Distance = (27.8 × 2.5) meters
Distance = 69.50 meters
Therefore the distance travelled is 69.50 meters.
According to Ohm's law for a portion of the circuit we have:
U=RI=>I=U/R=9/4=2.25 A