Answer:
See the answer below
Explanation:
A poker that will effectively and safely function to move pieces of coal or logs in a burning fire must be fireproof itself. Hence, to be as safe as possible, such <u>poker should be made from a material that is fireproof</u> and that does not conduct a lot of heat. Otherwise, the poker will catch fire/becomes too hot during the course of usage.
That would be a nebula, which is an interstellar cloud of hydrogen gas, dust, and plasma. It is the first stage of a star's cycle.
Answer:
The approximate number of decays this represent is
Explanation:
From the question we are told that
The amount of Radiation received by an average american is 
The source of the radiation is 
Generally

Therefore 
Also 
Therefore 
An Average american weighs 88.7 kg
The total energy received is mathematically evaluated as

Cross-multiplying and making x the subject


Therefore the total energy deposited is 
The approximate number of decays this represent is mathematically evaluated as
N = 
Where n is the approximate number of decay
Substituting values
Answer:
1. Recollapsing universe
2. Critical universe
3. Coasting universe
Explanation:
Recollapsing universe has dark matter density greater than critical density. While critical universe has its matter density equal to the critical sensity. Coasting universe on the other hand has much smaller matter density compared to critical density.
Note that the critical density is approximately 10^-20 grams/cm3