# MCAT Physics Questions — Constant Acceleration

How long does it take for a 1000kg object to fall 45m? (Ignore air resistance and assume constant acceleration from gravity of -10m/sec2)

A. 0.045 seconds

B. 3 seconds

C. 4.5 seconds

D. 9 seconds

##### Click for Explanation

Mass does not affect time for a projectile to fall in constant gravitational acceleration. For a 45m fall, use the equation y = v0t+1/2at2, with y = 45m, v0 = 0m/sec, and a = 10m/sec2.

45m = 1/2*(10m/sec2)t2, 9sec2 = t2, t = 3 seconds.

A) 0.045 seconds, incorrect, This answer divides the distance by the mass.

B) 3 seconds, correct.

C) 4.5 seconds, incorrect, This answer divides the distance by the gravitational acceleration.

D) 9 seconds, incorrect, This answer uses an incorrect formula proportional to t rather than t2.

## 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.

Create your Free Account to access our MCAT Flashcards 