Sunday, September 13, 2015


In the movie the Eraser Arnold Schwarzenegger's character is attempting to stop the sale of a newly developed rail gun to the Soviet Union. This rail gun is able to shoot aluminum bullets at the speed of almost the speed of light, which is about 3 x 10^8 meters per second. In one scene, Arnold has control of a rain gun and shoots an enemy in the chest and he goes flying. The question is, was how far the enemy flew accurate? Also, how far should've Arnold flown back when he did shoot the gun?

First, we must start with the before and after of Arnold shooting the gun. The formula we will be using will be (Ma)(Vfa)+(Mb)(Vfb)=(Ma)(Via)+(Mb)(Vib) where Ma is mass of Arnold. Vfa is Velocity final of Arnold. Mb is Mass of bullet. Vfb is Velocity final of bullet. Via is Velocity initial of Arnold. Vib is Velocity initial of bullet.

Lets say the mass of the bullet was .01 Kg since the movie didn't inform us of some of the specifics. We will put Arnold at about 110 Kg. Obviously the initial velocity of both the bullet and Arnold are 0. And, since the movie stated "close to the speed of light we will put it at around 3x10^7 meters per second.  All we need is the final velocity of Arnold. So that math will give us Vfa=-(.01Kg)(3x10^7m/s)/(110Kg). This gives us that Arnold will fly back at the speed of around 2727.27 meters per second. This proves that despite how large Arnold is, he would not have been able to hold his ground with this gun.

Now the before and after for the enemy. We will switch every "a" in the formula to an "e". We will also state that the bullet is lodged and stuck in the enemy so the enemy and the bullet have the same final velocity. So that gives us (Me)(Vfe)+(Mb)(Vfb)=(Me)(Vie)+(Mb)(Vib). Me will be 80 Kg. Mb is still .01 Kg. Vib is still going to be 3x10^7. And Vie is 0 meters per second. That will give us
Vfe=(.01Kg)(3x10^7m/s)/80Kg. That would make the enemy fly back at a speed of about 3750 meters per second. While the enemy did fly back very far, its just not quite far enough for good old physics.

Sunday, September 6, 2015

Mission Impossible 3

In the movie Mission Impossible 3, Agent Hunt is trying to once again save the world from terrorists. In one scene Agent Hunt must swing from one building to the next in order to get in the building. In order to know if it is in fact possible, lets look at some of the facts. The height of the taller building is 226 meters. The height of the smaller building was 162 meters. The two buildings are 47.55 meters apart. The time of the swing was about 15-20 seconds.

In the next scene, Agent Hunt is ironically being hunted by a drone on a bridge. The drone has blown a large hole on the bridge. He has to jump the gap in order to survive and destroy the drone. The gap of the bridge is approximately 20 feet. his acceleration was -9.81 meters/second squared. His initial velocity is 0 meters/second.

In the third scene, Agent Hunt is in a helicopter being chased by a helicopter through a field of windmill turbines. At one point Hunt's helicopter times the rotation of one turbine perfectly in order to get through leaving his enemies to be destroyed by the turbine. In order to know if this is possible we must know more. The rotation of the turbine was possibly about 1 rotation/second. The size of each blade was approximately 5 feet wide. The gap between the blade was about 15 feet. Now for the helicopter itself. By the looks of it the helicopter was maybe 15 feet tall and about 20 feet long. The helicopter must have been traveling about 80 mph so converted to meters per second is about 35.76 meters/second. The driver would have to time the rotation of the blades at just the right time in order to get through.