Answer:
The current amount of the Potassium-40 sample is approximately 37.521 grams. 
Explanation:
The amount of the sample of the radioactive isotope decays exponentially in time, the amount of mass of the sample as a function of time (
), in grams, is described below:
 (1)
Where:
 - Initial mass, in grams.
 - Time, in years.
 - Time constant, in years. 
The time constant can be found from half life (
), in years, described in statement:
 (2)
If we know that 
, 
 and 
, then the current amount of the sample is:




The current amount of the Potassium-40 sample is approximately 37.521 grams. 
 
        
             
        
        
        
C  average speed is used, which is total distance divided by total time.
Explanation:
From the analogy presented, we know that because the speed at which an object travels varies over time, the average speed is used. 
The average speed is is the total distance traveled divided by the total time taken. 
The average speed appropriately reflects changes in rate of speed with time. 
It accounts for moments where a car slows and speeds up. 
learn more; 
Speed brainly.com/question/8893949
#learnwithBrainly
 
        
             
        
        
        
Answer:P and S waves do refract more abruptly when they pass through the major transition zones separating the layers of the Earth. ... The Moho shows up in seismic data as a distinct change in wave speed due to a change in density of the rock across this boundary.
Explanation:
 
        
             
        
        
        
Cause they can't afford a house they don't have enough money for it hope this helps
        
                    
             
        
        
        
It began when Galileo tried to use his tidal theory to prove the movement of the Earth around the Sun. Galileo theorized that because of the Earth's motion, borders of the oceans like the Atlantic and Pacific would show one high tide and one low tide per day.