MCAT Physics Question — Object Acceleration
- Oct 08, 2017
- MCAT Question of the Day
An object rests on a plane, with an angle of incline, θ, an acceleration due to gravity, g, and a coefficient of friction μ between the object and the plane. Which of the following gives the acceleration of the object?
A. a = g sin θ
B. a = g (sin θ – cos θ)
C. a = g (cos θ – μ sin θ)
D. a = g (sin θ – μ cos θ)
Click for Explanation
The force of gravity down the plane is given by Fg = mg sin θ. The frictional force is given by Ff = μ mg cos θ.
Thus, we can set up the overall equation:
Fnet = Fg – Ff
Applying Newton’s Second Law, we can re-write the equation as:
ma = Fg – Ff
Substituting the equations given for Ff and Fg we get:
ma = mg sin θ – μ mg cos θ
Canceling out “m” throughout the equation and factoring out the “g” leaves us with:
a = g (sin θ – μ cos θ)
Thus, choice (D) is the right answer.
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 full-length 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 ConsultationSchedule Now
Free MCAT Practice AccountNeed great MCAT practice?
Get the most representative MCAT practice possible when you sign up for our free MCAT Account, which includes a half-length diagnostic exam and one of our full-length MCAT practice exams.Learn More