HESI A2 Physics

Correct Answer: C

Rationale: The correct answer is C (24 units). When you double the mass of both objects, the gravitational force between them increases by a factor of 4 (2 times 2). Therefore, the new force of attraction would be 12 units x 4 = 24 units. Choice A (3 units) and B (6 units) are incorrect because they do not account for the increase in mass. Choice D (48 units) is incorrect as it overestimates the effect of doubling the mass on the gravitational force.

Correct Answer: D

Rationale: The correct answer is D. Displacement is the change in position from the starting point to the endpoint, regardless of the path taken. In this case, traveling 500 miles northeast and then 500 miles southwest cancels out the movement, resulting in a displacement of 0 miles. However, the distance traveled is the total distance covered, which is 1,000 miles in this case. Therefore, option D correctly states that the displacement is 0 miles, and the distance traveled is 1,000 miles. Option A is incorrect because the distance traveled is not 0 miles. Option B is incorrect as the displacement is 0 miles. Option C is incorrect as both displacement and distance traveled are not 0 miles.

Correct Answer: A

Rationale: The correct answer is A because laminar flow is characterized by smooth, parallel layers of fluid particles moving in a uniform manner without mixing. This flow pattern occurs at low Reynolds numbers, where viscous forces dominate over inertial forces. Option B is incorrect as it describes turbulent flow, which is characterized by erratic and chaotic motion. Option C is incorrect because high viscosity would lead to more laminar flow, not hinder it. Option D is incorrect as incompressibility is a property of fluids and does not specifically characterize laminar flow.

Correct Answer: C

Rationale: Step 1: Energy consumption is typically measured in kilowatt-hours. Step 2: Power (in watts) is the rate at which energy is used. Step 3: Energy = Power x Time, as energy consumed is the product of power and time. Step 4: Therefore, the correct expression is Energy = Power x Time (Choice C). Summary: - Choice A is incorrect because power is the rate of energy consumption, not the total energy used. - Choice B is incorrect as it incorrectly combines time and energy without considering the power. - Choice D is incorrect as it rearranges the formula incorrectly, dividing energy by power instead of multiplying.

Correct Answer: B

Rationale: The correct answer is B: The bicycle has less kinetic energy than the car. Kinetic energy is calculated as KE = 0.5 * mass * velocity^2. Since both vehicles are traveling at the same speed, the one with greater mass (the car) will have more kinetic energy. The bicycle, being lighter than the car, will have less kinetic energy despite moving at the same speed. Other choices are incorrect because A is false as explained, C is incorrect as the vehicles have different masses, and D is incorrect as both vehicles are in motion, so both have kinetic energy.