A man drives a gokart around a circular track with a diameter of 50 m, at a rate of 314 m/minute. What is the frequency at which he circles the track in hertz (Hz)?
 0.0027 Hz
 0.03 Hz
 2 Hz
 6.25 Hz
Click for Explanation
B is correct. Hertz (Hz) is a measure of frequency with units of cycles per second, usually written as 1/sec. The number of cycles around the circle can be found by dividing the velocity by the circumference.
The circle circumference is (50 x pi) meters, or approximately 157 meters. The velocity of 314 m/min means that the driver completes 2 laps/min. The frequency in Hz is thus 2 laps/1 min x 1 min/60 sec = 1/30 Hz = 0.03 Hz.
 0.0027 Hz, incorrect, This answer results from mistaking the formula for the area of a circle (which is pi times the square of the radius) with the formula for circumference (pi times diameter).
 0.03 Hz, correct.
 2 Hz, incorrect, This is laps/min rather than laps/second.
 6.25 Hz, incorrect, This is the area divided by the velocity, with units of 1/min rather than 1/sec.
Want more MCAT practice?
We’ve got options for every schedule and learning style!
From the best online MCAT course created by top instructors with 524+ MCAT scores to the most representative fulllength practice exams and private tutoring, we can custom tailor your MCAT prep to your goals!
Not sure which option is right for you? Schedule a free MCAT consultation with an MCAT expert using the form below. No obligation, just expert advice.
Search the Blog
Free Consultation
Interested in our Online MCAT Course, OneonOne MCAT Tutoring or Med admissions packages? Set up a free consultation with one of our experienced Senior Student Advisors.
Schedule NowPopular Posts

MCAT Blog What's on the MCAT?

MCAT Blog How to Review MCAT FullLengths
Free MCAT Practice Account
Need great MCAT practice?Get the most representative MCAT practice possible when you sign up for our free MCAT Account, which includes a halflength diagnostic exam and one of our fulllength MCAT practice exams.
Learn More
Submit a Comment