A pulsar is a type of star. Among the fastest rotating stars known is a pulsar with radius 16km that is spinning at 716 revolution per second.

Question

How many kilometers per hour is a particle on the equator of the star traveling? Round to the nearest kilometer per hour.

 

b) the speed of light is about 3*10^8 meters per secon. What percent of the speed of light is the particle traveling

Answer 1

ω = 716 rev/s = 2π(716) rad/s

r = 16 km

 

v = rω = (16 km) [2π(716) rad/s] ≅ 71,980 km/s = 71,980,000 m/s

 

v = (71,980 km /s)(3600 s/hr) ≅ 259,128,000 km/hr

 

Percent of speed of light:

 

100(v/c) = 100 [(71,980,000 m/s) / 300,000,000 m/s) = 24% of the speed of light