Name ____________________ date __________ per_________ mail box___________ F=ma FORCE = MASS x ACCELERATION mass is in kg(kilograms) force in N (newtons) acceleration is in m/s2 (meters per seconds squared) During the last Apollo 15 moon walk, Commander David Scott performed a live demonstration for the television cameras. A heavy object (1.32-kg aluminum geological hammer) and a light object (0.03-kg falcon feather) were released simultaneously from approximately the same height (1.6 m) and were allowed to fall to the surface. The objects were observed to undergo the same acceleration and strike the lunar surface simultaneously, which was a result predicted by well- established theory, but a result nonetheless reassuring considering both the number of viewers that witnessed the experiment and the fact that the homeward journey was based critically on the validity of the particular theory being tested. Joe Allen, NASA SP-289, Apollo 15 Preliminary Science Report, Summary of Scientific Results, p. 2-11 Feather and Hammer Drop on Moon https://youtu.be/5C5_dOEyAfk WRITE THE FORMULA / SHOW WORK / CARRY UNITS / BOX ANSWER 1. How much force did Commander Scott’s hammer strike the lunar surface with that fateful day? Acceleration due to gravity on the moon is about 1/6 of that here on earth or 1.6m/s2. 2. How much force did the feather strike the lunar surface with? 3. If this same hammer having a mass of 1.32kg strikes the earth with a force of 12.936 newtons, what was the rate at which it accelerated? 4. What is the weight of the hammer on earth? 1 newton (force) ≈ 1/9.80665 kg = 0.10197 kg ≈ 102 grams (weight). 5. What does it weigh in pounds? 1kg ≈ 2.2 pounds 6. The mass of MLB Baseball is 145grams. Barry Bond 600th HR http://mediadownloads.mlb.com/mlbam/2014/11/25/mlbtv_pitsfn_10626397_1800K.mp4 Barry Bonds had to accelerate the ball to approximately 131912m/s2 to give it enough momentum to carry into the stands for a homerun. How much force did he swing the bat with? Force Newton’s First Law Friction Newtons (N) Newton’s Second Law Air resistance Net force Newton’s Third Law Terminal Velocity Balanced Force Acceleration Gravity Unbalanced Force Speed 1. ______________________This is a force on an object that is equal in Newton (N) measure and occurring in opposition directions. No change in position occurs, because there is no motion. Yet a force is still present. 2. ______________________This causes objects to change position because motion is being generated. 3. ______________________Also known as the Law of Inertia it states that an object at rest will remain at rest unless acted upon by another force. Further, an object in motion will remain in motion until acted upon by an outside force. 4. ______________________A net force acting on an object causes the object to accelerate in the direction that the force was applied. This is one of Newton’s Laws. 5. ______________________When one object exerts a force on a second object, the second object will always like wise in turn exert a force on the first. More classically put, “for every actions there is always an equal and opposite reaction.” 6. ______________________This is a push or pull that a body with mass exerts over another body with mass. 7. ______________________The unit of measure for calculating force 8. ______________________The combination of all forces acting simultaneously on an object. These forces can occur in the same direction or in opposite directions. 9. ______________________This is calculated by dividing change in velocity or speed by time. It is the rate of change in velocity or speed of an object in motion. 10. ______________________Determined by dividing distance traveled by time it takes to get there. Also described as the distance an object travels per unit of time. 11. ______________________This force occurs at the contact point between surfaces as they move or slide past one another. This force can occur between any of the states of matter. 12. ______________________This is a specific type of friction which occurs as an object moves through air or falls through the sky. Studies in aerodynamics are often aimed at limiting it. 13. ______________________On earth this is the maximum speed after acceleration a body can attain as it falls to the earth through air. To put it another way it is the constant speed that a freely falling object eventually reaches when the resistance of the medium through which it is falling prevents further acceleration. 14. ______________________The attractive force between objects which, is dependent on the objects’ masses and distance from one another. .