Answer to Question #149382 in Physics for Alyssa

Question

According to the Guinness Book of World
Records (1990 edition, p. 169), the highest
rotary speed ever attained was 2010 m/s (4500
mph). The rotating rod was 15.7 cm (6.2 in)
long. Assume the speed quoted is that of the
end of the rod.
What is the centripetal acceleration of the
end of the rod?
Answer in units of m/s
2
.
006 (part 2 of 3) 10.0 points
If you were to attach a(n) 1.91 g object to the
end of the rod, what force would be needed to
hold it on the rod?
Answer in units of N.
007 (part 3 of 3) 10.0 points
What is the period of rotation of the rod?
Answer in units of s.

Answer 1

1)

$$a=\frac{v^2}{r}\\a=\frac{2010^2}{0.157}=2.57\cdot10^7\frac{m}{s^2}$$

2)

$$F=ma=0.00191\frac{2010^2}{0.157}=4.92\cdot10^4\ N$$

3)

$$T=\frac{2\pi r}{v}=\frac{2\pi (0.157)}{2010}=4.91\cdot10^{-4}\ s$$