T5.1 2/2 points (graded) mass 2 T2 T1 cart 2 cart 1 Gravity mass 1 Consider the system in the diagram. Cart 1, cart 2, mass 1 and mass 2 have all the same mass. The mass of the two strings with tensions T1 and T2 is negligible (zero) and friction between the carts and the track is also negligible. (a) Draw free-body diagrams for each object (mass 1, cart 1 and cart 2 (with mass 2)), making sure the forces are drawn such that the direction of the net force for each object is communicated clearly. (b) What is the acceleration of the system? 2.45 correct (c) What is the ratio T1/T2 while the system is accelerating? 3/2 correct Some problems have options such as save, reset, hints, or show answer. These options follow the Submit button. T5.2 3/3 points (graded)
T= 7N T= 15N V, A ball with a weight of 2N is attached to the end of a string of length 2m. The ball is whirled (rotated) in a vertical circle clockwise. The tension in the string at the top of the circle is 7 N, and at the bottom it is 15 N. The speed of the ball is not the same at these two points. (a) Three students discuss the net force on the ball at the top. Angelica: "The net force on the ball at the top position is 7 N since the net force is the same as the tension." Bo: "The net force on the ball at the top position is 9 N. Both the tension and the weight are acting downward so you have to add them." Charles: "No, you are both wrong. You need to figure out the centripetal force () and include it in the net force." With which, if any of these students do you agree? Explain your Bo reasoning. correct (b) Now the students discuss the net force on the ball at the bottom. Angelica: "The net force on the ball at the bottom position is 15 N since the net force is the same as the tension."
Bo: "The net force on the ball at the bottom is 17 N, since you need to add the weight of 2 N to the tension of 15 N." Charles: "The net force on the ball at the bottom position is 13 N. I agree that you need to take into account both the weight and the tension, but they are in different direction so they will subtract." With which, if any of these students do you agree? Explain your Charles reasoning. correct (c) Is the ball going faster at the top or at the bottom? Compare the net force at the top and bottom to check your answer. Faster at the bottom correct Submit Some problems have options such as save, reset, hints, or show answer. These options follow the Submit button. T5.3 5/5 points (graded) Burglars (thieves) are trying to haul a safe up a frictionless ramp