The shortest distance between 2 concentric circles is the difference of their radii. Thus the answer is 8-2=6
Answer:
The answer would be A, 
Step-by-step explanation:
Remember, 
≠ 
, = 
.
a = = 
a = 
a = 
is negative
= , so is negative
Step-by-step explanation:
Frequency of a mass-spring system is:
f = √(k/m) / (2π)
Given f = 2/π Hz and m = 20 kg:
2/π Hz = √(k / 20 kg) / (2π)
4 Hz = √(k / 20 kg)
16 s⁻² = k / 20 kg
k = 320 kg/s²
k = 320 N/m
If the 20 kg mass is replaced with an 80 kg mass, the frequency is:
f = √(320 kg/s² / 80 kg) / (2π)
f = √(4 s⁻²) / (2π)
f = 2 Hz / (2π)
f = 1/π Hz
7.6 x 10^2 that's the answer
