Answer:B
Explanation:
For work to be done, the object must move some distance as a result of a force
 
        
             
        
        
        
Answer: gamma rays < ultraviolet light < radio waves
Explanation: We have to explain the ordering we take into account a relationship for electromagnetic wave, which is given by:
c=λ*ν c is the speed of light.  λ and ν are the wavelegth and the frequency of the waves.
Then we also know that the high frequency of these radiation correspond to the gamma ray (10^18 1/s) while the lowest correspond to radio wave (10^8 1/s) so:
The ultraviolet ligth is ranged at frequencies of 10^16 1/s located bewteen gamma and radio radiation.
as large frequency lower wavelength we can order these radiations from short to long wavelengths as follows:
gamma rays < ultraviolet light < radio waves
 
        
             
        
        
        
Answer:
60 Ω
Explanation:
R(com) = 15 Ω
1/R(com) = 1/R1 + 1/R2 + 1/R3 ..... + 1/Rn
1/15 = 1/20 + 1/R2
1/R2 = 1/15 - 1/20
1/R2 = (4 - 3) / 60
1/R2 = 1/60
R2 = 60 Ω
así, la combinada de resistencia necesaria es 60 Ω