MCAT Physics Question 30: Answer and Explanation

Home > MCAT Test > MCAT physics practice tests

Test Information

Question: 30

15. A consumer is comparing two new cars. Car A exerts 250 horsepower, while Car B exerts 300 horsepower. The consumer is most concerned about the peak velocity that the car can reach. Which of the following statements would best inform the consumer's decision? (Note: 1 horsepower = 745.7 W)

  • A. Car A and Car B both have unlimited velocities, ignoring nonconservative forces.
  • B. Car A will reach its peak velocity more quickly than Car B.
  • C. Car A will dissipate less energy to the surroundings than Car B.
  • D. Car A will have a lower peak velocity than Car B.

Correct Answer: A

Explanation:

Horsepower is a unit of power, as evidenced by the name and the conversion factor given in the question stem. Power is a rate of energy expenditure over time. Given unlimited time, both cars are capable of unlimited increases in (kinetic) energy, meaning that they have unlimited maximum velocities. The fact that Car B has a higher power rating means that it will reach any given velocity faster than Car A, eliminating choice (B). There is not enough information to make any judgments on the efficiency of the cars, eliminating choice (C). While it may take longer for Car A to reach a given velocity, both cars have unlimited maximum velocities according to the information given in the stem, eliminating choice (D).

Previous       Next