For every actions, there is an opposite reaction.
Answer:
9155 years old
Explanation:
We use the following expression for the decay of a substance:

So we first estimate the value of k knowing that the half-life of the C14 is 5730 years:

so, now we can estimate the age of the artifact by solving for"t" in the equation:

which we can round to 9155 years old.
The train is moving at 50 m/s and Emma is walking down the aisle with 1 m/s speed in the same direction of train. The relative velocity of Emma with respect to other passengers pf the train would be 1 m/s. This is because, the train is not moving relative to them and only emma is moving at 1 m/s. If a person observes from outside, Emma would have (50 +1) m/s = 51 m/s velocity.
relative velocity when two objects are moving in same direction as oberved from outside observer:

relative velocity when two objects are moving in the opposite directionas oberved from outside observer:

I’m almost 100 percent sure it’s the first one
So that international people don't mistake units for others. ex 1 inch could be mistaken for 1 cm in non American countries