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Pgeske
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If a meteor entered the Earth's atmosphere at 11 or so km/sec and impacted the Earth with a direct hit (by impact time it is 4 kg), what would the force of impact be? I only need a rough answer.
Pgeske said:Alright, but how would I account for air resistance? Would that reduce the energy of impact by a huge amount? I know that if there wasn't wind resistance, the energy of impact would be extremely high, but what would the energy of impact be with air resistance?
cjl said:11 km/s is the speed an object will have if it starts far from Earth with zero speed, and is accelerated to the ground by gravity alone. If it starts with some initial speed, its impact will be faster than 11 km/s.
Pgeske said:If a meteor entered the Earth's atmosphere at 11 or so km/sec
cjl said:Yes, but it is a reasonable assumption for the speed it will have at the top of the atmosphere.
Borek said:I see what you are saying, but you don't need any assumption about the entry speed, as entry speed is given.
JohnKingtamer said:What if a series of asteroids hit the moon with each both slowing the moon and deflecting it increasingly toward earth?
Trevormbarker said:Something that small would likely burn in the atmosphere on the way down. If it did make it F=MA
Acceleration due to gravity is 9.8 m/s^2 so ~ 40 N
ryan_m_b said:Are you sure you're using F=MA correctly here? i.e. in the context of the question asked.
Trevormbarker said:I thought so, correct me if I am wrong, the thread name was how much force would a 4 Kg meteor impact Earth with. What am I doing incorrectly?
ryan_m_b said:This question is possibly going to reveal to PF how simplistic some of my understanding is but here goes...
F=MA refers to the energy needed to accelerate an object of given mass i.e. how much force does it take to accelerate a 4kg object at 1g = 40N per second.
However the OP isn't "what force does a 4kg asteroid undergo when falling to Earth", it's how much energy would the 4kg asteroid release. That would be worked out by figuring out the kinetic energy of the asteroid.
For another way to see why F=MA doesn't provide an answer to the OP consider this, using it the way you have done (where A is the acceleration in the gravity field of Earth) would give the same result for a 4kg asteroid traveling at 11kmps and one traveling at 111,000kmps.
Trevormbarker said:I see what your saying, sorry about this missunderstanding, So according to the OP should one not just use Ek = 1/2mv^2 and use different values for v depending on how fast the meteor is moving
The force of impact from a 4 kg meteor can be calculated using the formula F=ma, where F is the force, m is the mass of the meteor, and a is the acceleration due to gravity. Assuming a gravitational acceleration of 9.8 m/s^2, the force of impact would be approximately 39.2 Newtons.
The force of impact from a meteor can be affected by several factors, including the mass and velocity of the meteor, the angle of impact, and the composition of the impact surface. Additionally, air resistance and atmospheric conditions can also play a role in altering the force of impact.
The force of a 4 kg meteor would be relatively low compared to larger objects, such as asteroids or comets, which can range in mass from several tons to kilometers in diameter. However, it would still be significant enough to cause damage upon impact, depending on the velocity and angle of impact.
Yes, the force of impact from a 4 kg meteor can be predicted using mathematical models and simulations. Scientists use data on the mass, velocity, and trajectory of the meteor to estimate the force and potential effects of impact on the earth's surface.
There are several strategies for mitigating the force of impact from a meteor, including early detection and tracking, deflection techniques, and impact avoidance planning. These strategies are continuously being researched and developed by scientists and organizations such as NASA to better prepare for potential meteor impacts in the future.