5 Matching Annotations
1. Mar 2017
1. People that do the activity of parkour are athletic humans capable of controlling their body and using it to the fullest extent. Numerous people hang off of buildings or do handstands with one hand on the edge of tall buildings which show great stability. A person that does a handstand on an edge of a tall building has great strength as well as stability because of their form. Their center of gravity is on the arm that is holding them up, and they are able to stabilize themselves by moving their other arm as well as their legs in a position that "pushes" all the weight onto one spot allowing them to balance.

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3. Feb 2017
4. www.independent.co.uk www.independent.co.uk
1. Eddie Hall, the strongest man in the world is the first man to lift 500kg. That itself is an amazing feat, and by using the height of the 500kg in relevance to the ground, we can calculate the work lifted. Eddie Hall's height is 6ft 3, and since deadlifts require the person to lift a bar at their torse, we can estimate the lift height to be 3 feet or .91m. Knowing that the weight is (500kg)(9.8N), we can do (500kg)(9.8N) (.91m) to get 4459J which is the work lifted.

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5. www.efastball.com www.efastball.com
1. The formula for Kinetic Energy is 1/2 m v^2. Based on this site, the average speed of a pitch by a 16 year old is 76 MPH. Based on this data, we can find the Kinetic Energy of a 16-year old's pitch by doing KE = 1/2 (.145 KG) (76^2) = 418.76 J

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1. Mountain climbers and skydivers experience GPE. You explained that GPE = (mass) (gravity) (height), and I agree with you that formula is correct. You then gave an even better explanation using someone on top of Mount Everest, and you said that the person's GPE was 7,370,384 J which is calculated from the height which is 8848 x the force 9.8 x 85 which is his mass. The GPE calculation is also different from someone on a ground since they have a different height.