# Physic

posted by
**Janki Patel**
.

I am confuse about this one question can some one please help me.

The Navy wants a new airplane launcher for their aircraft carriers and you are on the design team. The launcher is effectively a large spring that pushes the plane for the first 3.49 meters of the 24.2-meter long runway. During that same time, the plane's jet engines supply a constant thrust of 5.4 x 104 N for the entire length of the runway. The 2000 kg planes need to have a velocity of 45 m/s by the end of the runway. What should be the spring constant (in kN/m) be for the launcher?

Thank You so much!!!