HESI Exams Quizlet Physics

Correct Answer: B

Rationale: Step 1: Work is defined as the product of force and displacement in the direction of the force. Step 2: In this scenario, the object is stationary, meaning there is no displacement. Step 3: Without displacement, work done is zero. Step 4: Therefore, the correct answer is B: Not performed. Summary: A: Incorrect because work requires displacement. C: Incorrect as partial work implies partial displacement, which is not the case here. D: Incorrect as it is conclusive that work is not performed due to the absence of displacement.

Correct Answer: A

Rationale: To calculate momentum, we use the formula p = mv, where p is momentum, m is mass, and v is velocity. Since momentum is conserved, the momentum of the 2,000-kg car is equal to the momentum of the 1,500-kg car. Setting the two momentum equations equal to each other, we get 2000*15 = 1500*v, where v is the velocity of the 1,500-kg car to generate the same momentum. Solving for v, we get v = (2000*15) / 1500 = 20 m/s. Therefore, to generate the same momentum as the 2,000-kg car, the 1,500-kg car would need to accelerate to 20 m/s. Choice A is correct. Choices B, C, and D are incorrect as changing the mass or a combination of adding mass and velocity will not lead to the 1,500-kg car generating

Correct Answer: B

Rationale: To determine the power rating of the lamp, we use the formula Power = Energy / Time. Given the lamp consumes 60 Joules per second, the power rating is 60 Joules / 1 second = 60 Watts (Choice B). The other choices are incorrect because A is too low, C is not a valid unit for power, and D is not necessary as power can be calculated based on energy consumption alone.

Correct Answer: B

Rationale: The correct answer is B because as a raindrop falls, air resistance increases, counteracting the force of gravity. Initially, gravity pulls the raindrop down, causing it to accelerate. However, as the raindrop gains speed, air resistance becomes stronger, eventually balancing out the gravitational force. This results in a constant velocity rather than acceleration. A: Gravity does pull the raindrop down, but it doesn't do so at a constant rate. The acceleration due to gravity is constant but is countered by air resistance. C: The mass of the raindrop remains constant as it falls, so its mass decreasing is not a factor in its speed. D: Objects in motion do not necessarily decelerate over distance; in the case of the raindrop, air resistance prevents further acceleration.

Correct Answer: A

Rationale: The correct answer is A: 10 m/s. Velocity is calculated by dividing the distance traveled by the time taken. In this case, velocity = 100m / 10s = 10 m/s. Choice B, 90 m/s, is incorrect because it is not the accurate calculation. Choice C, 110 m/s, and choice D, 1,000 m/s, are both incorrect as they do not align with the correct formula for calculating velocity. The key is to remember that velocity is a vector quantity that includes both speed and direction, and in this case, we are only concerned with the speed of the object, making choice A the correct answer.