What is that?? Please tell us
 
        
             
        
        
        
Explanation:
A) Use Hooke's law to find the spring constant.
F = kx
40 N = k (0.4 m)
k = 100 N/m
B) Period of a spring-mass system is:
T = 2π √(m / k)
T = 2π √(2.6 kg / 100 N/m)
T = 1 s
Frequency is the inverse of period.
f = 1 / T
f = 1 Hz
 
        
             
        
        
        
If the desk doesn't move, then it's not accelerating. 
If it's not accelerating, then the net force on it is zero.
If the net force on it is zero, then any forces on it are balanced.
If there are only two forces on it and they're balanced, then they have equal strengths, and they point in opposite directions.
So the friction on the desk must be equal to your<em> 245N</em> .
 
        
             
        
        
        
Answer:
3.52176 x 10^-10 N
Explanation:
Fg = 3.52176 x 10^-10 Newton
 
        
             
        
        
        
Answer:
Yes
Explanation:
Testing electricity is a good conductor of electricity.