Savannah Sharp Brooke Young Nicole McIntosh Newton’s First Law Savannah Sharp Brooke Young Nicole McIntosh

State and Explain Major Concepts Newton's First Law- An object at rest stay's at rest and an object in motion stay's in motion at the same speed and same direction unless acted upon by an unbalanced force. It is also known as the law of inertia.

Historical Perspective Copernicus formulated a theory about the moving earth. He didn't publish the theory in his lifetime though because he feared persecution. Galileo in the sixteenth century proposed that Copernicus's idea was reasonable. He tested his theory's by showing that no force was necessary to keep an object moving. He observed that with the absence of friction a moving object would naturally keep moving. Galileo said that every material object has resistance to change, he called this inertia. Newton later restated Galileo's law.

Application’s of the Concept One representation of inertia is a air hockey table. If you slide a hockey puck across concrete it will come to a stop very quickly. If you were to slide a hockey puck across ice, it would continue sliding for awhile before it came to a stop. A puck on a air hockey table however, would slide for an extremely long time. This is because there is little to no friction acting on the hockey puck. Other examples of Newton's First Law are: snapping a table cloth from beneath dishes or a car accident in which the vehicle is hit from the front or behind.

Think and Explain 1. Newton's Law is explained here because when the car is hit it jolts the car forwards, but the person's body is still at rest. The car did move, but the person sitting in the car did not. If they were not sitting in the seat they would have flew out of the seat. headrests help by stopping your neck from completely bending backwards. 2. Relative to the ground the ball stays in about the same place, but relative to the wagon the ball moved from the middle to the end. 3. By zigzagging the elephants weight would be hard for them to control and they would tip, much like driving too fast around a corner. 4. The volume changes. 5. a. The string tension is higher on the string above because it has another string pulling against it along with the mass of the ball. b. If the string snapped downwards the top string is still more likely to break.

Think and Explain 6. It is best to hold it with the handle down because the weight of the hammer is pushing down as well as the force pushing down. 7. You could determine which one had more mass by squeezing the container and shaking it to feel a difference. 8. 667.2 Newton's 9. a. By holding the apple in your hand, it is still moving at the same speed. b. If you drop the apple it no longer is going the same speed. 10. That scenario does not work because the helicopter would have to be very high up to get our of the Earth's orbit.

Review Questions 1. Natural Motion is straight up and down, objects seek their natural resting places; violent motion is imposed motion The result of forces pushed and pulled. 2. His ideas about moving earth were very controversial so he didn't publish anything to avoid prosecution. 3. If there enough friction, an object will gradually slow down. The smoother the plane, the less friction. If there was an absence of friction an object could roll forever without any force pushing it. 4. The speed will stay constant. 5. It rolled up to nearly the same height. 6. Yes, if you snap a table cloth out from underneath dishes correctly, the friction is barley there so the dishes stay at rest. If you slide a hockey puck on a city street it will not go far, but if you slide it across ice it slides for a longer distance. If you slide the puck across an air hockey table (on which there is basically no friction), it will slide with no apparent loss of speed. 7. A bicycle needs to be pedaled because the tires create friction against the ground. If you were on a very smooth surface, the bike would need to be pedaled less.

Review Questions 8. None. 9. Yes, yes, no. 10. Yes, no. 11. Mass is a measure of te actual material in a body. 12. No because even though they weigh the same, their mass is different, so the elephant would have a larger effect hitting you. 13. 4.4 pounds. 14. At your feet. The vertical force of gravity effects only the vertical motion of the coin. 15. Because inetia allows the pillow to move with you. The horizontal speed of the pillow stays the same as you, and the jet.

Framing the Demonstration

Background Info and Initial Observation The inertia of an object depends on it's mass. Different objects have different inertias, the more mass- the more inertia.

Question or Hypothesis We Are Investigating How much inertia do different cans have? We hypothesize that the lighter cans will have less inertia.

General Statement of How We Will Conduct Our Experiment We will kick three different cans with the same amount of force. One will be empty, one filled with water, and one with sand.

Apparatus and Materials Needed 1. Three empty bottles or cans 2. Sand and Water 3. A balance 4. Someone's foot

Step by Step Instructions 1. Fill one bottle with sand and one with water. Leave the third can empty. 2. Measure the sand filled bottle and the water filled bottle. 3. Have the same person tap each with their foot lightly. First the empty one, the one with water, and the one with sand.

Safety Precautions 1. Make sure that the lids are properly secured on each bottle before kicking them. 2. Do not kick the bottles with enough force to break them.

Table of Results Water Bottles Distance of Water Bottles in Feet Empty 6 Water 3.75 Sand 3.50

Analysis of Results After performing the experiment, we found the empty water bottle had the least amount of resistance and the water bottle full of sand had the most resistance.

Conclusions Supported by Evidence After performing the experiment we found the lighter bottles were much easier to knock over because there was less mass holding it in its place. While the bottles with more mass were much more difficult to knock over.

Evaluation of Hypothesis/ Answer to Question After conducting the experiment we found our hypothesis to be correct because the lighter bottles were much easier to knock over. They took much less force to move, and moved farther than the heavier bottles.