<u>for instance, steel has a higher thermal conductivity than plastic. Hence, the steel plate gives away heat to the ice block faster than a plastic block does. As a result, ice melts faster on a steel plate than on a plastic one. Faster an object draws heat, the colder it feels.</u>
 
        
                    
             
        
        
        
The answer 1 is 
The best-known use of radio waves is for communication; television, cellphones and radios all receive radio waves and convert them to mechanical vibrations in the speaker to create sound waves that can be heard.Electromagnetic radiation is transmitted inwaves or particles at different wavelengths and frequencies.
the answer 2 is 
 Radio Waves: Instant Communication 
Microwaves: Data and Heat
 i think the answer number 3 is 
It is all about wavelength versus tunnel diameter. The wavelength of GPS is about 20cm it would happily propagate in any normal tunnel if it could get in but the earth and other structures absorb it. AM radio (600kHz - 1500kHz) cannot propagate in any normal tunnel because the wavelength is too long (500m-200m) relative to the diameter, and thus gets reflected at the entrance. FM (100MHz ~ 3m) would propagate and it does for a while but then it suffers reflections
        
                    
             
        
        
        
Answer: hello question b is incomplete attached below is the missing question 
a) attached below
b) V = 0.336 ft/s
Explanation:
Elongation ( Xo)  = 16/ 7 feet 
mass attached to 4-foot spring = 16 pounds
medium has 9/2 times instanteous velocity
<u>a) Find the equation of motion if the mass is initially released from the equilibrium position with a downward velocity of 2 ft/s</u>
The motion is an underdamped motion because the value of β < Wo 
Wo = 3.741 s^-1
attached below is a detailed solution of the question
 
        
             
        
        
        
<span>Your flexibility decreases.  But if you exercise or stretch a few times a  week you can slow down the process </span>
        
                    
             
        
        
        
Its when the animal repeats what it is taught similar to a child you never really teach them to lie it just happens because they have seen other people do it