a jet fighter plane is launched from a catapult on an aircraft carrier. it reaches a speed of 42 m/s at the…

Explanation:

Step1: Identify known quantities

The jet starts from rest (initial velocity ( u = 0 , \text{m/s} )), final velocity ( v = 42 , \text{m/s} ), time ( t = 2.0 , \text{s} ), and acceleration is constant. We can use the formula for average velocity to find the displacement (length of catapult), since for constant acceleration, average velocity ( \bar{v}=\frac{u + v}{2} ), and displacement ( s=\bar{v}\times t ).

Step2: Calculate average velocity

( \bar{v}=\frac{0 + 42}{2}=21 , \text{m/s} )

Step3: Calculate displacement (length of catapult)

Using ( s=\bar{v}\times t ), substitute ( \bar{v} = 21 , \text{m/s} ) and ( t = 2.0 , \text{s} ): ( s=21\times2.0 = 42 , \text{m} )

Answer:

42 m (corresponding to the option "42 m")