<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: 2.73m/s
Explanation:
Potential energy of the water is turned into kinetic energy
mgd = mv^2/2
Where m = mass of water
g = acceleration due to gravity = 9.81m/s^2
d = depth of the water = 0.38m
v = velocity of leaking water
m × 9.81 × 0.38 = mv^2/
eliminate m on both sides and multiply through by 2
7.4456 = v^2
v = sqrt(7.4456)
v = 2.73m/s
As the skateboard rolls down the ramp it loses potential energy and gains kinetic energy.
Answer:
energy is the capacity to do work
Answer:
The bottom of the sea is 25 m below sea level.
Explanation:
Given data
Mass = 6.1 × 

We know that Buoyant force on the tank is equal to gravity force of the tank.



1020 ×
= 6.1 × 
= 598039.21 
We know that
= W × L × H
598039.21 = 300 × 80 × H
H = 25 m
Therefore the bottom of the sea is 25 m below sea level.