Here Power = Voltage * Current
So, Voltage = Power/Current
Put the values,
V = 240/2
V = 120 V
In short, Your Final Answer would be: 120 Volts
Hope this helps!
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:
An unbalanced force means that there are more than one forces with different directions or magnitudes affecting the object. In this case, the vector addition of the forces should be done. The vector addition will result a net force. The object will move in the direction of the net force.