Reposting this question again....need more responses?

Question

A fighter jet is launched from an aircraft carrier with the aid of its own engines and a steam-powered catapult. The thrust of its engines is 2.40 105 N. In being launched from rest it moves through a distance of 87 m and has a kinetic energy of 4.90 107 J at lift-off. What is the work done on the jet by the catapult?

Tried two different ways and both were wrong.....what am i doing wrong

Thrust*Distanc+Wc*D=Ke
2.40*10^5*87+Wc*87=4.90*10^7J
Wc=2.347

1st attempt
W=Chane Kinetic Energy
Wc=Fs=(2.40*10^5)87=20880000J
Wc=323218.391

2nd attempt
We+Wc=change KE
Wc=2.347
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Additional Details
2 minutes ago
For the response
The KE at lift of is 4.9x10^7, meaning that 2.612x10^7 J comes from the catapult.
how did you get the 2.612X10^7<

Answer 1

This is what I think:

Total KE of jet = work done by thrust + work done by catapult

Work done = Force x distance

So work done by thrust = (2.09 x 10^7J)

Hence from the difference work done by catapult =

KE - work done by thrust

4.90 x 10^7 J - 2.09 x 10^7 J = 2.812 x 10^7 J

Answer 2

Your error on your first attempt was multiplying the work done by the catapult by distance. Your equation should read
(2.40*10^5)*87 + Wc = 4.90*10^7J
Then
2.088*10^7 + Wc = 4.90*10^7J
Wc = 4.90*10^7J - 2.088*10^7 J
Wc = 2.812*10^7 J