Step by step solution :
standard deviation is given by :

where,
is standard deviation
is mean of given data
n is number of observations
From the above data, 
Now, if
, then 
If
, then 
if
, then 
If
, then 
If
, then 
so, 



No, Joe's value does not agree with the accepted value of 25.9 seconds. This shows a lots of errors.
Answer:
The force constant is 
The energy stored in the spring is 
Explanation:
From the question we are told that
The mass of the object is 
The period is 
The period of the spring oscillation is mathematically represented as

where k is the force constant
So making k the subject

substituting values


The energy stored in the spring is mathematically represented as

Where x is the spring displacement which is given as

substituting values


B) a rock being tossed high into the air
It is like that, except most nails are steel or stainless steel, slowing to rusting process to about 5 years.
Answer:
not true because the mass from the heavy car will cause it to damage more
Explanation: