<h3><u>Answer;</u></h3>
Carbon-14 levels in a sample are undetectable after approximately 9 half lives
<h3><u>Explanation;</u></h3>
- <em><u>The half life of Carbon-14 is 5,730 years . Half life is the time taken by a radioactive material to decay by half of its original mass. Therefore, it would take a time of 5730 years for a sample of 100 g of carbon-14 to decay to 50 grams</u></em>
- <em><u>A period of 50,000 years, is equivalent to; </u></em>
<em><u> 50,000÷5,730 </u></em>
<em><u>= 8.73 half lives</u></em>
<em>Which is approximately equal to 9 half lives.</em>
- Therefore, if the age of an object older than 50,000 years cannot be determined by radiocarbon dating, then <em><u>Carbon-14 levels in a sample are undetectable after approximately 9 half lives</u></em>.
Answer: The time period of the given wave with frequency of 425 Hertz is 0.0023 seconds.
Explanation:
Frequency of the wave = 425 Hertz =


The time period of the given wave with frequency of 425 Hertz is 0.0023 seconds.
Answer:
a)40100m/s
b)-4.348x10^- m/s^2
Explanation:
to calculate the change in the planet's velocity we have to rest the speeds
ΔV=-22.8-17.3=-40.1km/s=40100m/s
A body that moves with constant acceleration means that it moves in "a uniformly accelerated movement", which means that if the velocity is plotted with respect to time we will find a line and its slope will be the value of the acceleration, it determines how much it changes the speed with respect to time.
When performing a mathematical demonstration, it is found that the equations that define this movement are as follows.
Vf=Vo+a.t (1)\\\\
{Vf^{2}-Vo^2}/{2.a} =X(2)\\\\
X=Xo+ VoT+0.5at^{2} (3)\\
Where
Vf = final speed
Vo = Initial speed
T = time
A = acceleration
X = displacement
In conclusion to solve any problem related to a body that moves with constant acceleration we use the 3 above equations and use algebra to solve
for this problem we have to convert the time interval ins seconds, we know that a year has 53926560s
t=1.71years=53926560*1.71=92214417.6
then we can use the ecuation number 1 to calculate the aceleration
Vf=-22.8km/s
Vo=17.3km/s
Vf=Vo+at
a=(vf-vo)/t
a=(-22.8-17.3)/92214417.6
a=-4.348x10^-7 km/s^2=-4.348x10^- m/s^2
Answer:
Its is dividing by 2
Explanation:
It starts with 100 them it goes to 50, 25, 12.5 so its a cycle of dividing by 2
Answer:
1800J
Explanation:
Given parameters:
Weight of the book = 20N
Total distance covered = 45m + 15m + 30m = 90m
Unknown:
Total work performed on the books = ?
Solution:
To solve this problem we must understand that work done is the force applied to move a body through a certain distance.
So;
Work done = Force x distance
Work done = 20 x 90 = 1800J