As you can see from the video, Samuel L. Jackson and the Dwayne Johnson jumped off the top of the building only held by a rope tied around their legs. We wanted to find out how much tension was in the rope to support only one of the actors (Samuel L. Jackson) and if the tension in the rope could break his legs.
Samuel L. Jackson: Information Height-6ft 2in, or 1.88m Weight-225 lbs, or 102kg Building: Measured the height of each story to find the total height, plus the bottom floor which had a higher height. 3.675 meters per story, 10 stories and bottom story was 6.72 meters so the total building got to be 43.47m Potential Energy: We used the weight(kg), the height of the building, and gravity to find the total potential energy at the top of the building. PE= (102)*(43.47)*(9.8)= 43,452.6N Kinetic Energy: We used the equation 0.5mv^2. First we needed to find the velocity, so we used tracker, tracking Jackson down the building to find out that his speed right before he hit the ground would be equal to 27.40, then we used his weight, 102kg to find the Kinetic Energy. KE=0.5*102*(27.40^2)=38288.76
To find the tension the rope has on Jackson we used the equation T+ WT=ma. First we found the weight by doing the equation W=mg or 102kg X 9.8 m/s = 999.6 N. We already have his weight as 102kg. Then we needed to find the acceleration right before the rope retracted back upwards. So, we used Tracker and at the same point as the velocity the acceleration was equal to 18.05 m/s^2. Plugging all of this information into this equation would create T + 999.6N = 102kg X 18.05m/s^2. We then found the tension to be 841.5N for the rope against Jackson. Per say the rope was is tied to Jacksons ankle. Since he is technically now part of the rope could his leg bone withstand the amount of tension without breaking? The answer is yes. On average, the human femur bone can withstand a tension of 1599 N before breaking. There is still a margin of possibility that his leg could break but looking at statistics, it is very unlikely.
Works Cited "Dwayne Johnson - IMDb." The Internet Movie Database (IMDb). Web. 12 Jan. 2012.. "Energy of Falling Object." Web. 12 Jan. 2012.. "Samuel L. Jackson Weight." Ever Wonder How Much A Celebrity Weighs? — Celebrity Weights. Web. 12 Jan. 2012..