The formula is=1/2(m x v^2)
so = 1/2*(0.05)*(310)^2
ans is =2402.5 joules
        
             
        
        
        
I do not agree with the statement.
The "substance" can be a compound.  It's "pure" 
as long as there's nothing else in it but its name.
'Pure' water is 100% H₂O with nothing else in it.
'Pure' table salt is 100% NaCl with nothing else in it.
'Pure' carbon dioxide is 100% CO₂ with nothing else in it.
These example substances are all compounds, not elements.
 
        
             
        
        
        
Answer:
The average velocity is 
 and
 and  respectively.
 respectively.
Explanation:
Let's start writing the vertical position equation : 

Where distance is measured in meters and time in seconds.
The average velocity is equal to the position variation divided by the time variation.
 = Δx / Δt =
 = Δx / Δt = 
For the first time interval :
t1 = 5 s → t2 = 8 s
The time variation is :

For the position variation we use the vertical position equation :
 
 

Δx = x2 - x1 = 1049 m - 251 m = 798 m 
The average velocity for this interval is 

For the second time interval : 
t1 = 4 s → t2 = 9 s


Δx = x2 - x1 = 1495 m - 125 m = 1370 m 
And the time variation is t2 - t1 = 9 s - 4 s = 5 s
The average velocity for this interval is :

Finally for the third time interval : 
t1 = 1 s → t2 = 7 s
The time variation is t2 - t1 = 7 s - 1 s = 6 s
Then


The position variation is x2 - x1 = 701 m - (-1 m) = 702 m 
The average velocity is 

 
        
             
        
        
        
Q=mc(t2-t1)
Q=2.06kg x specific heat of oil(191-23)
Q=2.06×c×168
Q=143.62q
        
             
        
        
        
'Doing work' is a way of transferring energy from one object to another, energy is transferred when a force moves through a distance.
If i explain with formula 
Work done (J) = Energy transferred (J)
So more energy, more work done bc u transferred more energy to move the object and doing the work. and if you only use a little of energy, the work done also only a little.