The second scene of “good physics” to be analyzed is a classic rope swing which is something that is common in many pirate productions. In this scene Will Turner has rescued Captain Jack Sparrow from his cell in Port Royal’s jail and Jack has now devised a plan to commandeer one of the Royal Navy’s battleships, the HMS Interceptor. Jack and Will use a submerged boat in order to get to another ship, the HMS Dauntless, which is anchored off shore.
After climbing aboard and commandeering the Dauntless, the Royal Navy is made aware of the current situation and dispatches the HMS Interceptor to apprehend Jack and Will. Upon reaching and boarding the Dauntless, Commodore Norrington orders a search of the ship. While the Commodore and his crew are not looking Jack and Will swing across to the Interceptor (motion can be viewed at 2:28 to 2:31) escaping Norrington and his troops. When analyzing Will’s swinging motion it became apparent that this motion is plausible in the world of Physics.
When mapping Will’s motion it was determined that the distance he traveled is 4.8 meters The question which must be asked in this scene is, "does Will have enough momentum to allow him to travel the allotted distance"? Will’s motion is much like a pendulum, beginning at rest , x meters above rest position, accelerating to its maximum velocity (directly in the middle of the motion) and returning to its original amplitude (distance released) x meters above the ground. Will’s motion however only shows half of this. He begins with a velocity of 0 m/s and accelerates to his maximum velocity (approximately when he reaches the Interceptor). When mapped it is noted that his maximum velocity is 4.24 m/s and the total time of the motion is 2.3 seconds. Now one can solve and calculate the maximum distance Will can travel given the following information. This calculation can be seen below.
t=2.3s
Vf=4.24m/s a= (Vf-Vi)/t
=4.24/2.3
= 1.84 m/s^2
Vi=0m/s
dphoto=4.8m
dmax=?
dmax=1/2at^2+Vit
=1/2(1.84)(2.3)^2+0
dmax=4.9m
According to the measured information it is plausible that Will can swing the distance from the Dauntless to the Interceptor. The photo distance in this scene was measured to be 4.8 meters and the calculated distance was 4.9 meters. Will can make the Interceptor with 0.1 meters to spare. Therefore, it can be concluded that this scene contains an example of "good physics".
After climbing aboard and commandeering the Dauntless, the Royal Navy is made aware of the current situation and dispatches the HMS Interceptor to apprehend Jack and Will. Upon reaching and boarding the Dauntless, Commodore Norrington orders a search of the ship. While the Commodore and his crew are not looking Jack and Will swing across to the Interceptor (motion can be viewed at 2:28 to 2:31) escaping Norrington and his troops. When analyzing Will’s swinging motion it became apparent that this motion is plausible in the world of Physics.
When mapping Will’s motion it was determined that the distance he traveled is 4.8 meters The question which must be asked in this scene is, "does Will have enough momentum to allow him to travel the allotted distance"? Will’s motion is much like a pendulum, beginning at rest , x meters above rest position, accelerating to its maximum velocity (directly in the middle of the motion) and returning to its original amplitude (distance released) x meters above the ground. Will’s motion however only shows half of this. He begins with a velocity of 0 m/s and accelerates to his maximum velocity (approximately when he reaches the Interceptor). When mapped it is noted that his maximum velocity is 4.24 m/s and the total time of the motion is 2.3 seconds. Now one can solve and calculate the maximum distance Will can travel given the following information. This calculation can be seen below.
t=2.3s
Vf=4.24m/s a= (Vf-Vi)/t
=4.24/2.3
= 1.84 m/s^2
Vi=0m/s
dphoto=4.8m
dmax=?
dmax=1/2at^2+Vit
=1/2(1.84)(2.3)^2+0
dmax=4.9m
According to the measured information it is plausible that Will can swing the distance from the Dauntless to the Interceptor. The photo distance in this scene was measured to be 4.8 meters and the calculated distance was 4.9 meters. Will can make the Interceptor with 0.1 meters to spare. Therefore, it can be concluded that this scene contains an example of "good physics".