Calculating Average Force Due to Air Resistance in Projectile Motion

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SUMMARY

The discussion focuses on calculating the average force due to air resistance for a projectile with a mass of 0.750 kg, launched vertically with an initial velocity of 18.0 m/s, reaching a maximum height of 11.8 m. The energy lost due to air resistance is equivalent to the work done by air resistance, which can be determined by comparing the initial kinetic energy and the final potential energy. The initial kinetic energy is calculated using the formula KE = 0.5 * m * v^2, while the potential energy at maximum height is PE = m * g * h. The difference between these energies yields the work done by air resistance, allowing for the calculation of the average force.

PREREQUISITES
  • Understanding of basic physics concepts such as kinetic energy and potential energy.
  • Familiarity with the equations of motion for projectile motion.
  • Knowledge of the work-energy principle.
  • Basic algebra skills for manipulating equations.
NEXT STEPS
  • Calculate the initial kinetic energy using the formula KE = 0.5 * m * v^2.
  • Determine the potential energy at maximum height using PE = m * g * h.
  • Learn how to calculate work done by air resistance using the work-energy principle.
  • Explore the effects of different variables on projectile motion, such as mass and initial velocity.
USEFUL FOR

Students studying physics, educators teaching projectile motion concepts, and anyone interested in understanding the effects of air resistance on projectiles.

dbtarz
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A projectile has a mass of .750kg and is shot straight up with an initial velocity of 18.0m/s. If the projectile rises to a max height of 11.8m, determine the magnitude of the average force due to air resistance. Can anyone help me with this?
 
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The energy lost due to air resistance equals the work done by the air.
 
I don't understand?
 
Suppose there is no air resistance. Can you calculate how high the projectile would go?

Given that, can you calculate the energy that is lost due to air resistance?
 
Drawing pictures and listing knowns/unknowns is great help. You know the mass, the height/displacement, and the velocity. These give you the initial kinetic energy and the final potential energy, and the initial energy is always equal to the final energy plus the work done by friction/air resistance/etc (the wasted energy).

It is all pretty straight-forward. ^^
 

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