HESI A2 Physics Practice Test

Correct Answer: D

Rationale: To calculate momentum, we use the formula: momentum = mass x velocity. Given mass = 5 kg and velocity = 5 m/s, the momentum is 5 kg x 5 m/s = 25 kg⋅m/s. Therefore, choice D (25 kg⋅m/s) is the correct answer. Choice A (10 kg⋅m/s) is incorrect as it doesn't account for both mass and velocity. Choice B (16.2 km/h) is incorrect as it is a unit conversion for speed, not momentum. Choice C (24.75 kg⋅m/s) is incorrect as it doesn't match the calculated momentum value.

Correct Answer: A

Rationale: To find the period, we use the formula: Period = 1 / Frequency. Given the frequency as 25 beats per second, we calculate 1 / 25 = 0.04 seconds. Therefore, the correct answer is A. Choice B (0.25 s) is incorrect as it represents the inverse of the frequency, not the period. Choice C (0.4 s) and D (4 s) are also incorrect as they are not the correct calculations based on the given frequency.

Correct Answer: B

Rationale: Step-by-step rationale: 1. Bernoulli's principle states that in a flowing fluid, an increase in flow velocity leads to a decrease in pressure. 2. As the fluid flows faster in a constricted pipe, kinetic energy increases while pressure energy decreases. 3. This relationship between velocity and pressure is consistent for incompressible fluids. 4. Therefore, when the flow velocity increases in a constricted pipe, the pressure will decrease. Summary: - Choice A is incorrect because Bernoulli's principle applies universally to all incompressible fluids. - Choice C is incorrect because pressure changes with velocity according to Bernoulli's principle. - Choice D is incorrect as pressure decreases when velocity increases, as per Bernoulli's principle.

Correct Answer: B

Rationale: To calculate the magnitude of the resulting force, we use Coulomb's Law: \(F = k \cdot \frac{{|q_1 \cdot q_2|}}{{r^2}}\), where \(k\) is the electrostatic constant, \(q_1\) and \(q_2\) are the charges, and \(r\) is the distance between them. Plugging in the values, we get \(F = 9 \times 10^9 \cdot \frac{{3 \times 10^{-6} \cdot 2 \times 10^{-6}}}{{(0.3)^2}} = 0.18\) N. Choice B is correct because it correctly calculates the force using Coulomb's Law. Choices A, C, and D are incorrect because they either miscalculate the force or provide unrealistic values that do not align with the physics of electrostatic forces.

Correct Answer: C

Rationale: The correct answer is C (3 ohms) because in a series circuit, the total resistance is the sum of individual resistances. Since the circuit has 3 same-size resistors, each resistor must have the same resistance. Therefore, the total resistance of the circuit is 3 times the resistance of one resistor. Using Ohm's Law (V = IR), with V = 9V and I = 1A, we can find the total resistance (R) as 9V = 1A * R. Thus, R = 9 ohms for the whole circuit. Since each resistor has the same resistance, each resistor must be 1/3 of the total resistance, which is 3 ohms. Choice A (9 ohms) is incorrect because it represents the total resistance of the circuit, not the resistance of each individual resistor. Choice B (6 ohms) is incorrect because it does not consider the equal division of resistance among the three resistors