5 . Compare the results between the two experiments using the table below by circling answers for each experiment and explaining your choices. Experiment Did the glider gain or Change in Explanation lose energy during glider's energy this process? (AE glider) push to the gain positive left lose negative no energy change zero push to the gain positive right lose negative no energy change zero Using the law of conservation of energy, what do you expect the sign of the work is in your two experimental cases? Is the sign of work the same or different? Explain. Moold s no how everspell ow sill Soold erll no pool Insignco s shoxe brind A brist afunnotes lb efl worle of woled awons weld (Wildsub Checkpoint. Please continue working. gold no 10167 Joold ent to Mamsonigela In the rest of the tutorial, we will learn the tools to figure out how much work is done on the glider in total, the work done by each force, and relate this to the change in the glider's total energy. Tutorial Section 4.2 - The definition of work, and conservation of energy 1. Positive work on a block. A block is moving to the left in outer space while touching only an astronaut's hand. The astronaut exerts a constant force on the block. The work done on the block by the hand is positive. The hand's force is either to the left or to the right (but you are not told which directly). Draw arrows to show the direction of the displacement of the block and the direction of the force by the hand. Displacement of the block Force on block by hand a. Explain how you chose the direction of the force on the block by the hand. b . Does the total energy of the block increase, decrease, or stay constant? Explain. (Assume the block does not change potential energy.) Hint: Is the block speeding up, slowing down, or moving with constant speed? 45Imagine that you are told that the positive direction is to the left. Does this change the sign of the work for your force and displacement drawn? Is the object's change in energy different in this coordinate system? Explain. Imagine that you are told that the positive direction is to the right. Does this change the sign of the work for your force and displacement drawn? Is the object's change in energy different in this coordinate system? Explain. 2. Negative work on a block. A block is moving to the left in outer space while touching only an astronaut's hand. A hand exerts a constant force on the block. The work done on the block by the hand is negative. The hand's force is either to the left or to the right (but you are not told which directly). Draw arrows below to show the direction of the displacement of the block and the direction of the force by the hand. Displacement of the block Force on block by hand a. Explain how you chose the direction of the force on the block by the hand. b. Does the total energy of the block increase, decrease, or stay constant? Explain. Assume the block does not change potential energy.) Hint: Is the block speeding up, slowing down, or moving with constant speed? 46Tutorial Section 4.1 - An illustrative experiment to introduce work and energy PLEASE DO NOT MOVE THE GLIDERS WITHOUT THE AIR TRACK BEING TURNED ON! Without the air, the coefficient of friction is much higher and the gliders will scratch the air track. Place the glider on the track and give it a quick push to the right. Release contact with the glider before the glider passes point A. What is the speed of the glider as it moves through photogate A? Record your result here. Consider the part of the experiment between when your hand first touches the glider (when it is at rest) and when it moves through the first photogate. What is the change in the glider's total energy (4E) during this time? Calculate your answer in Joules. Assume the glider's potential energy does not change. (Hint: what type of energy does change for the glider during the experiment?) 3. Now repeat the experiment so that the glider is pushed from the other direction. What is the speed of the glider as it moves through photogate A? Record your result IA - T here. SBA-T - 8 PIT alspoton9 - s Again, consider the part of the experiment between when your hand first touches the glider (when it is at rest) and when it moves through the first photogate. What is the change in the glider's total energy (AE) during this time? Assume the glider's potential energy does not change. 44