Answer:
(a) There are 3.17 times more shakes in a second than seconds in a year.
(b) Humans have existed for 9067.72 universe seconds.
Explanation:
(a) First we calcule how many seconds are in a year. One year have 365 days, one day has 24 hours, one hour has 60 minutes and one minute has 60 seconds, so:

Now, we calculate how many shakes are in a second:

Finally, we calculate how many more shakes in a second are there than seconds in a year:

(b) Using a simple rule of three we can calculate how many "universe seconds" have humans existed, recall that 1 day has 86400 seconds:
1010 years--------->86400s
106 years----------> x seconds

Solution :
a). From Newtons second law,
F = ma
The total tension force is 2T.
∴ 2T - (m + M)g = (m+ M)a
Then



b). From the person,
F = ma
T - Mg + N = Ma
or N = Ma + Mg - T
= (63 x 9.8) + (52 x 9.8) - 600
= 617.4 + 509.6 - 600
= 527 N
Answer:
In a closed-loop system, matter is used to generate energy, and the energy generated is used to produce matter, and the cycle goes on without end.
Explanation:
A closed-loop system is one in which materials or energy is recycled without end through a production cycle. This means that a raw material is used to produce a finished product, and the finished product at the end of its use cycle is converted back and used as a raw material to produce more of it again. Energy and matter can also be cycled in the same way in an energy and matter closed-loop system, converting matter to energy, and the energy is put back into the production of more of the matter.
D. There is a known constant concentration of C14 in Nature. As we consume living things to survive our bodies (made of carbon) stop replenishing our body's carbon (we stop eating) and start to decay. Since we know the 1/2 life of C14 and the ratio of C14 to normal C12 we can determine fairly accurately how long ago a thing stopped consuming carbon (e.g. when it died)