the correct answer is option d.
6.67*10-3 hrs
Answer:

Explanation:
To determine the age, we need to know how much U have become Pb, so first we have to calculate the Pb moles present in a sample:


The percentage of U degradation:


Assuming that the life time is linear:


Answer:
Newton's first and third law of Motion
Explanation:
The laws applying in the example Newton's first and third laws of Motion.
- The first law states that any object at rest (ie. not moving) will stay at rest until it is forced to move by an external force. In this case, said force were the propulsion gases ignited.
- As the hot gases were pushed out from the engine nozzle, there was another force <em>equal in magnitud but opposite in direction</em> (as the gases went down, that force went upwards), said force is directly responsible for the rocket taking off. That is an example of the third law.
Well, in an atom, there are an equal number of protons and electrons so they cancel each other out.