Answer:
An Object is positively charged if it has more Positive Electrons in that object
 
        
             
        
        
        
Answer:
4.29 millimeters
Explanation:
Bats emit ultrasound waves: in air, ultrasound waves travel at a speed of 

The frequency of the waves emitted by this bat is:

Therefore we can find the wavelength of the wave emitted by the bat by using the relationship between speed, frequency and wavelength:

 
        
             
        
        
        
Answer:
Explanation:19,2 or 0/4 or 5 or 40,4
 
        
             
        
        
        
The marbles that are 'more energetic' fall out of the tray, in the same way particles have enough energy to escape and turn into a gas.