# Work done by a catapult given engine thrust, distance moved, and kinetic energy of liftoff

Alexandra Fabiello
Homework Statement:
Jet fighter planes are launched from aircraft carriers with the aid of their own engines and a catapult. If in the process of being launched from rest, the thrust of a jet's engines is 2.10 * 10^5 N and after moving through a distance of 90 m the plane lifts off with a kinetic energy of 4.20 * 10^7 J, what is the work done on the jet by the catapult?
Relevant Equations:
Work total = change in kinetic energy
force = change in kinetic energy / change in distance
force = 4.2e7 J/90 m = 466666.6667 N
this minus 2.10e5 = 2.57e5 N rounded
This is incorrect, so I'm probably missing a formula or something.

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Homework Statement: Jet fighter planes are launched from aircraft carriers with the aid of their own engines and a catapult. If in the process of being launched from rest, the thrust of a jet's engines is 2.10 * 10^5 N and after moving through a distance of 90 m the plane lifts off with a kinetic energy of 4.20 * 10^7 J, what is the work done on the jet by the catapult?
Homework Equations: Work total = change in kinetic energy
force = change in kinetic energy / change in distance

force = 4.2e7 J/90 m = 466666.6667 N
this minus 2.10e5 = 2.57e5 N rounded
This is incorrect, so I'm probably missing a formula or something.
You are asked for the work done, not the force.

Alexandra Fabiello
You are asked for the work done, not the force.

Whoops, I mixed up 'change in kinetic energy' with force somehow.

Thanks, that worked!