13)
there are 2π radians in 1 revolution, and there are 60 seconds in 1 minute, so keeping that in mind, then,

14)


15)
what is the radians per seconds "w" in revolutions per minute? just another conversion like in 13)
M = 90 kg,
On Mars: g = 3.71 m/s²
Weight = m · g = 90 kg · 3.71 m/s² = 333.9 N
1 N = 0.2248 lbf
333.9 · 0.2248 = 75.06072 lbf ≈ 75 lbf
The answer is -- A. Exactly one solution
A=2-b
2-b/b=3
2-b=3b
B=1/2
A=3/2
A-b=3/2-1/2=1
Answer is 1