Imagine that you take the Earth bucket-spring-cork onto an elevator. Compared to the bucket-spring-cork on Earth, is the cork closer to the surface of the water, closer to the bottom of the bucket, or in the same relative position? Imagine an identical bucket-spring-cork system is stationary on the surface of the Jupiter where the acceleration due to gravity is 2.65 times greater than on Earth.
#Circular motion body diagrams free
You are holding the bucket so that it is stationaryĭraw a Free Body diagram of all the forces acting on the cork.Īs Archimedes realized a long time ago, the upward “buoyant” force on the cork is equal to the weight of the water that the cork has displaced. A cork is attached to the other end of the spring and is suspended motionless under the surface of the water. If your answer to Part A is yes, where did Verne make his mistake? If your answer is no, explain.Ī bucket of water has a one end of a spring soldered to the bottom, as shown. Is there a contradiction between the inhabitants inside the projectile experiencing normal gravity (sitting on the chairs) and the dog’s body outside the projectile not falling back to the Earth? The next day the people looked out the porthole and saw that the dog’s body was still floating just beside the projectile. They put the dog’s body out the hatch and into space. Thus the people and dogs would experience normal gravity, and be able to, for example, sit on the chairs just as if the projectile were sitting on the Earth’s surface. Verne reasoned that at least until the projectile got close to the Moon it would be in the Earth’s gravitational field during its journey. Inside the projectile was furniture, three people and two dogs. In Jules Verne’s From the Earth to the Moon (1865) a huge cannon fires a projectile at the moon. Able to identify the assumptions a model relies upon.īefore reading any further, it might help to watch this video. Able to evaluate the consistency of different representations. Able to extract information from a representation.
What would be the motion of this balance for each of the six cases you investigated? Explain. S uppose that instead of a single mass suspended from a spring scale, the apparatus consisted of a pan balance with two masses with equal values on the pans. How do the readings of the scale compare to what you felt for each of the six cases? Moving down and slows down as it approaches a floor where it will stop.įor each of the values of Part C, estimate the uncertainty in the value. Initially stationary and begins moving down the tower. Moving up and slows down as it approaches a floor where it will stop. Initially stationary and begins moving up the tower. Calculate the acceleration of the elevator when it is: Use the diagram to explain the reading of the scale.Ĭhoose the upward direction as positive and the downward direction as negative, and select one of your Team’s data. Sketch a Free Body Diagram of all the forces acting on the mass during the motion being investigated for the seven cases. Going down just at the end, as the elevator is slowing down.ĭescribe the readings of the scale for each of the seven cases. Going down just at the start, as the elevator is speeding up.
Going up just at the end, as the elevator is slowing down. Going up just at the start, as the elevator is speeding up. Able to analyse data appropriately.Īs preparation for this Module you took a ride on one of the elevators in the tower, paying attention to the reading of the spring scale of the weight of a 0.75 kg mass for seven different cases: Describe what is observed without trying to explain. Able to use available equipment to make measurements. Failure to do this will cause a deduction of one mark from your Practical mark. If Activity 2 is assigned, before the Practical take a ride in one of the elevators and note what happens to the reading of the scale for the six cases listed in Activity 2 below.įor your convenience, a form for writing down some data from your observations is available at: ElevatorForm.pdfįill out the form and bring it to your Practical. In each of the four elevators in the tower of the Physics building is mounted a spring scale with a mass hanging from it. Preparation for Activity 2 of this Module If you are going to push down on the top of the table to make it unstable, where is the best place to push? Explain. A round table is supported by three legs.
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