Fan Cart Physics Explore Learning

 ASSESSMENT QUESTIONS: Print Page NIEASTSA STEVENSON Q1 Q2 Q3 Q4 Q5 SCORE Your Results saved for      2/5 class Advanced Physical Science: Period 2 Questions & Answers 1. According to the graph of v vs. t below, what was the initial velocity of the cart? A. 0.0 m/s B. 0.5 m/s C. 1.0 m/s D. 1.5 m/s Correct Answer: B. 0.5 m/s Explanation: According to the graph, the initial velocity was about halfway between 0 m/s and 1 m/s, so 0.5 m/s is the best choice. You answered this question correctly! 1/7 2. The acceleration of the cart shown below is represented in the given graph. If a second block is added to the cart, what might be the resulting acceleration? A. 0 m/s/s B. 0.27 m/s/s C. 0.4 m/s/s D. 0.53 m/s/s Correct Answer: B. 0.27 m/s/s Explanation: The fan exerts a force on the cart, so the acceleration will not be zero. This eliminates answer A. Because the total mass of the cart is increased by the addition of another mass, the acceleration of the cart will be lower than it was with just one mass. This eliminates answers C and D. Answer B is the only possibility. You answered this question incorrectly. Your answer was C. 3. A cart is set up as shown below, with three fans directed to the left and two of the fans running. The motion of the cart is represented by the v vs t graph shown. If the experiment were repeated with all three fans running, what might the resulting v vs t graph look like? 2/7 A. Graph A B. Graph B C. Graph C D. Graph D Correct Answer: D. Graph D Explanation: Turning on the third fan will cause the velocity of the cart to increase more 3/7 quickly. (In other words, the acceleration of the cart will be greater.) The value for the acceleration is equal to the slope of the v vs t graph, so the correct answer will be a graph that has a greater slope than that shown in the question. The slope in Graph A is negative. Graph B shows a graph with a 0 slope. Graph C shows a graph with a slope that is positive but less than that in the question. Only Graph D shows a line with a greater slope than that of the given graph, so it is correct. You answered this question incorrectly. Your answer was C. 4. Which of the following cart congurations could produce the x vs t graph shown? A. Cart A B. Cart B C. Cart C D. Cart D 4/7 Correct Answer: B. Cart B Explanation: The graph shows that the cart initially is traveling in the positive direction. As time passes it gradually slows and eventually reverses its direction to travel in the negative direction. A curve such as this results from a net force acting in the negative direction. This means that a fan must be directed in the negative direction (pointing to the right, forcing the cart back to the left). Answer B is the only set-up that shows a negatively directed net force. To duplicate the graph with the Gizmo, set the initial velocity of the cart to 2.0 m/s. Place one weight and one fan on the cart, and change the direction of the fan so that it blows air to the right, as shown. You answered this question correctly! 5. A cart with one fan on it blowing to the left and carrying one block produces the x vs t graph shown. If this cart were carrying three blocks instead of one, with the fan still blowing the same direction, what could the x vs t graph look like? 5/7 A. Graph A B. Graph B C. Graph C D. Graph D Correct Answer: C. Graph C Explanation: Both of the given carts have one fan blowing, in a positive direction. This means that both carts will be accelerating in a positive direction. But, the rst cart is carrying one block, while the second cart is carrying three blocks. This means that the second cart will accelerate more slowly than the rst cart. Graph A cannot be correct, because it describes a cart that slows down and eventually starts moving in the negative direction. Graph B cannot be correct, because it describes a cart that is not speeding up at all. Graph D cannot be correct, because it describes a cart that is accelerating more quickly than the given cart. Only Graph C could be correct. It describes a cart that is accelerating in a positive direction, but not as quickly as the given cart. You answered this question incorrectly. Your answer was D. 6/7