It does produce 'sound' ... a compression wave traveling through the air. But your ears don't hear a sound that's vibrating less than 20 or 30 times every second. If you could swing your pendulum that fast, you could hear the sound of its vibrations pushing the air around.
        
             
        
        
        
Answer:
The cartilage is the structure that reduces friction between joints. 
Explanation:
Cartilage is the tissue between the bone joints. They are composed of several membranes and cellular groups. One of them called synovial membrane which provides lubricant to the edges of tissue that are touched by the bones. Reducing the friction and absorbing it so the body can move without obstacles. 
 
 
        
             
        
        
        
The microwave ovens rotate at a rate of about 0.105 rev/s.
The microwave rotation is the number of revolutions in a unit of time. To change the unit for angular velocity, assume that the quantity is multiplied by the unit it has. Then change to the desired units. The angular velocity is denoted by ω and has a magnitude of 6.3 rev/min.
ω = 6.3 rev/min

- 1 minute = 60 seconds
- The revolution unit didn't change


ω = 0.105 rev/s
Learn more about Angular velocity here: brainly.com/question/29344944
#SPJ4
 
        
             
        
        
        
Answer:
D
Explanation:
The bottom of the mountain is not correct because your trying to stop.
The top is of the mountain is when you gain energy.
The middle is when you have the most kinectic energy.
 
        
                    
             
        
        
        
The moon, because the acceleration due to gravity is less.