MCAT Physics Quiz

Once you’re familiar with the physics that will be tested on the MCAT, try out this MCAT Physics Quiz.

Question 1

Mechanical advantage and efficiency are both ratios. Which of the following is true regarding the quantities used in these ratios?

A. Mechanical advantage compares values of work; efficiency compares values of power.

B. Mechanical advantage compares values of forces; efficiency compares values of work.

C. Mechanical advantage compares values of power; efficiency compares values of energy.

D. Mechanical advantage compares values of work; efficiency compares values of forces.

Answer 1

B: Mechanical advantage is a ratio of the output force generated given a particular input force. Efficiency is a ratio of the useful work performed by a system compared to the work performed on the system.

Question 2

Two wooden balls of equal volume but different density are held beneath the surface of a container of water. Ball A has a density of 0.5 g/cm^3, and ball B has a density of 0.7 g/cm^3. When the balls are released, they will accelerate upward to the surface. What is the relationship between the acceleration of ball A and that of ball B?

A. Ball A has the greater acceleration.

B. Ball B has the greater acceleration.

C. Balls A and B have the same acceleration.

D. It cannot be determined from information given.

Answer 2

A: Using Newton’s second law, F(net) = ma, we obtain the follow-ing equation:

F(buoy) − mg = ma

Thus,

(F(buoy) − mg) / m = (F(buoy) / m) − g

Both balls experience the same buoyant force because they are in the same liquid and have the same volume (F(buoy) = ρVg). Thus, the ball with the smaller mass experiences the greater acceleration. Because both balls have the same volume, the ball with the smaller density has the smaller mass (m = ρV), which is ball A.

Question 3

F represents the electrostatic force exerted on charged particle S by charged particle R.

mcat physics

In the figure, the magnitude of the electric force on R due to S is:

A. F/2.

B. F.

C. 2F.

D. 4F.

Answer 3

B: According to Newton’s third law, if R exerts a force on S, then S exerts a force with equal magnitude but opposite direction back on R. Therefore, the magnitude of the force on R due to S is F.

Question 4

Each of the resistors shown carries an individual resistance of 4 Ω.

mcat physics

Assuming negligible resistance in the wire, what is the overall resistance of the circuit?

A. 16 Ω

B. 8 Ω

C. 4 Ω

D. 3 Ω

Answer 4

D: The resistance of the three resistors wired in series is equal to the sum of the individual resistances (12 Ω). This means that the circuit functionally contains a 12 Ω resistor and a 4 Ω resistor in parallel. To determine the overall resistance of this system, use this formula:

1/R(p) = 1/R(1) + 1/R(2) = 1/(12Ω)  + 1/(4Ω) = (1 + 3)/(12Ω) –> R(p) = 3Ω

Question 5

A scientist looks through a microscope with two thin lenses with m1 = 10 and m2 = 40. What is the overall magnification of this microscope?

A. 0.25

B. 30

C. 50

D. 400

Answer 5

D: The overall magnification of a system of multiple lenses is simply the product of each lens’s magnification. In this case, that is 10 × 40 = 400.