Car Collisions
Physics of Car Crashes INTERNAL - Notes
INJURIES TO A HUMAN:
During a car crash, there are three different collisions that occur. The first one is the collision of the car and the opposing object, the second is the human inside the car and the car itself. The final collision is the ones that occur within the human body itself.
BRAIN:
The human brain is protected by the cranial cavity or the skull. The brain is suspended in a substance called the cerebral spinal fluid, which is denser than the skull itself. In a collision, the brain and cerebral spinal fluid begin both begin to move, at different rates than each other. The cerebral spinal fluid will then displace the brain in the opposite direction than the original impact, as the fluid moves …show more content…
An impulse is something that changes an objects momentum, and is the product of force and the time which that force acts. Impulse is expressed in the equation Impulse=Ft, where F is the force and t is the time on which that force is applied. Impulse is essentially the change in momentum of an object.
If we a car with a mass of 1500kgs was driving at a velocity of 20ms-1, its momentum would be 30,000kgms-1. If we assume that this vehicle crashed into a solid concrete wall, with the time taken being 0.05s, we can calculate the force that the car exerts on the wall and the force the wall exerts on the car. All we need to do is rearrange the equation Impulse=Ft to F=Impulse/t. Because the impulse is the change in momentum (final-initial), the impulse would be 30,000kgms-1.
30,000/0.05 = 600,000N.
The force that is applied to the wall and the wall applies to the car is a colossal 600,000N. What this would look like to a human is simple. The stronger bone in the body, the femur would, on average, take about 4000N to break, meaning that the force of this crash could break the human femur 150 times. Because there are 206 bones in the human body, the force of this crash could break about 73% of the total bones in the human body, most likely killing …show more content…
Ek=1/2 x 1735 x 422
Ek=876.5 x 422 =>876.5 x 1764
Ek=1,546,146 J
1,546,146/366536.5 = 4.22
As we can see through these equations, when we double the speed of an object, we quadruple the amount of energy involved in a car collision. This is why speed is such a crucial factor in the outcome of a car collision, as even increasing the speed a meagre 10kmph, can significantly impact the outcome of a car collision an end a life of a loved one.
FEATURES IN CARS TO HELP INCREASE STOPPING DISTANCE AND HELP PASSENGERS:
Cars and other automobiles are engineered in a certain way and include certain features to help the occupants of the vehicle’s survival being the top priority of the car. Engineers design automobiles so that the occupants/passengers’ survival is the top priority. One of these features in cars is the crumple zone.
Early automobile designs saw extremely rigid car frames that were very resistant in various accidents. Because of this flawed theory, the cars would end up surviving the collision, however, the occupants of the car would not survive the fatal injuries.
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INJURIES TO A HUMAN:
During a car crash, there are three different collisions that occur. The first one is the collision of the car and the opposing object, the second is the human inside the car and the car itself. The final collision is the ones that occur within the human body itself.
BRAIN:
The human brain is protected by the cranial cavity or the skull. The brain is suspended in a substance called the cerebral spinal fluid, which is denser than the skull itself. In a collision, the brain and cerebral spinal fluid begin both begin to move, at different rates than each other. The cerebral spinal fluid will then displace the brain in the opposite direction than the original impact, as the fluid moves …show more content…
An impulse is something that changes an objects momentum, and is the product of force and the time which that force acts. Impulse is expressed in the equation Impulse=Ft, where F is the force and t is the time on which that force is applied. Impulse is essentially the change in momentum of an object.
If we a car with a mass of 1500kgs was driving at a velocity of 20ms-1, its momentum would be 30,000kgms-1. If we assume that this vehicle crashed into a solid concrete wall, with the time taken being 0.05s, we can calculate the force that the car exerts on the wall and the force the wall exerts on the car. All we need to do is rearrange the equation Impulse=Ft to F=Impulse/t. Because the impulse is the change in momentum (final-initial), the impulse would be 30,000kgms-1.
30,000/0.05 = 600,000N.
The force that is applied to the wall and the wall applies to the car is a colossal 600,000N. What this would look like to a human is simple. The stronger bone in the body, the femur would, on average, take about 4000N to break, meaning that the force of this crash could break the human femur 150 times. Because there are 206 bones in the human body, the force of this crash could break about 73% of the total bones in the human body, most likely killing …show more content…
Ek=1/2 x 1735 x 422
Ek=876.5 x 422 =>876.5 x 1764
Ek=1,546,146 J
1,546,146/366536.5 = 4.22
As we can see through these equations, when we double the speed of an object, we quadruple the amount of energy involved in a car collision. This is why speed is such a crucial factor in the outcome of a car collision, as even increasing the speed a meagre 10kmph, can significantly impact the outcome of a car collision an end a life of a loved one.
FEATURES IN CARS TO HELP INCREASE STOPPING DISTANCE AND HELP PASSENGERS:
Cars and other automobiles are engineered in a certain way and include certain features to help the occupants of the vehicle’s survival being the top priority of the car. Engineers design automobiles so that the occupants/passengers’ survival is the top priority. One of these features in cars is the crumple zone.
Early automobile designs saw extremely rigid car frames that were very resistant in various accidents. Because of this flawed theory, the cars would end up surviving the collision, however, the occupants of the car would not survive the fatal injuries.
(