The initial velocity of the stone is 0 ft/s. Given the initial velocity (Vi), final velocity (Vf), and acceleration due to gravity (g), the distance may be calculated through the equation,
                                     d = ((Vf)² - (Vi)²) / 2g
Substituting the known values,
                                     d = ((96 ft/s)² - 0))/ (2x32.2)
The value of d is 143.10 ft. 
        
             
        
        
        
At rest because if the distance is not changing, then it is not moving any further, so it must not be moving! The time keeps going no matter what, so the distance, whether it is 0 m or 10,000 km, if the y is horizontal the distance does not change. 
        
             
        
        
        
<span>the statement that is true regarding flexibility is : b. a joint's range of motion will be lost if the joint is not used regularly.
Our body is like a machine. If we not constantly heat it up, our body will be more prone to injury. We can see that the old people who lived within the tribe in the middle of the mountain are far stronger than the one who lived in the city.</span>
        
                    
             
        
        
        
The power of the engine is 320 W.
<u>Explanation:</u>
Power may be defined as the rate of doing work (or) work done per unit time. One unit of energy is used to do the one unit of work.
                           Power = Work done / Time taken
Given, Force = 80 N,    height = 5 m , final velocity = 4 m/s
To calculate the power, we must know the time taken. 
To find the time, use the distance and speed formula which is given by 
                               Time = Distance / speed 
Here distance = 5 m and speed = 4 m/s
                               Time = 5 / 4 = 1.25 s.
Now,          Power = work done / time 
                               = (F * d) / t  = (80 * 5) / 1.25
                   Power = 320 W.
The standard unit of power is watt (W) which is joule per second.