Question

A fighterjet is launched from an aircraft carrier with the

aidof its own engines and a steam powered catapult. The thurst of
itsengine2.3*10^5N. In being launched from rest it moves through
adistance 87m and has KE 4.5*10^7J at lift off.What is the work
doneon the jet by the catapult.

Answer 1

The work done on the jet is
`W_(jet) = 2.49* 10^(7) J`

Given:

Force, F =
`2.3* 10^(5) N`

Distance moved by the jet, x = 87 m

Kinetic Energy, KE =
`4.5* 10^(7) J`

Solution:

Now, to calculate the work done on the fire fighter jet by the catapult, we find the difference between the KE of the jet at lift off and the work done by the engines.

This difference provides the amount of work done on the jet and is given by:

`W_(jet) = KE - W_(engines)` (1)

Now, the work done by the engines is given by:

`W_(engines) = Fx = 2.3* 10^(5)* 87 = 2.001* 10^(7) J`

Now, using eqn (1):

`W_(jet) = 4.5* 10^(7) - 2.001* 10^(7) = 2.49* 10^(7) J`