Answer:
Energy conservation.
Explanation:
The 1st Law of Thermodynamics is a statement about energy conservation. It states that 
, which means that if we <u>substract the work W done</u> by the system to the <u>heat Q given</u> to the system we get the <u>change in the internal energy</u> 
, so any excess in energy given to the system appears as internal energy, stating that energy is conserved.
 
        
             
        
        
        
Answer:
Stretch can be obtained using the Elastic potential energy formula.
The expression to find the stretch (x) is 
Explanation:
Given:
Elastic potential energy (EPE) of the spring mass system and the spring constant (k) are given.
To find: Elongation in the spring (x).
We can find the elongation or stretch of the spring using the formula for Elastic Potential Energy (EPE).
The formula to find EPE is given as:

Rewriting the above expression in terms of 'x', we get:

Example: 
If EPE = 100 J and spring constant, k = 2 N/m.
Elongation or stretch is given as:

Therefore, the stretch in the spring is 10 m.
So, stretch in the spring can be calculated using the formula for Elastic Potential Energy.
 
        
             
        
        
        
Answer:
the velocity of the car is 0.875 m/s
Explanation:

therefore the V of car is 0.875 m
 
        
             
        
        
        
1) 4°C : It has the highest density as shown on the graph.
2) Water expands when it freezes, making it less dense than just water.
3) The ice would sink to the bottom, then the rest of the water would freeze as well, the entire lake/river/whatever will freeze eliminating the organisms that live there.
 
        
             
        
        
        
The answers false I believe