A. Decrease by approximately 10%
B. Increase by approximately 10%
C. Increase by approximately 25%
D. Remain unchanged
Click for Explanation
The problem states that Q is to remain unchanged. That allows us to set up the following equation:
Q = A_{1}v_{1} = A_{2}v_{2}
Plugging in 1 as the original values, we get:
1 x 1 = 0.81 x v_{2}
Because the radius was decreased to 90% of its original value, the crosssectional area will be reduced to 81% of its original value (A is proportional to radius squared and 0.92 = 0.81)
r_{2} = 0.9r_{1}
A_{2} = 0.81A_{1}
Solving for v_{2} we get 1.23. Thus the velocity increased by approximately 25%, making choice (C) correct.
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 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