   Chapter 5, Problem 42P

Chapter
Section
Textbook Problem

An airplane of mass 1.50 × 104 kg is moving at 60.0 m/s. The pilot then increases the engines thrust to 7.50 × 104 N. The resistive force exerted by air on the airplane has a magnitude of 4.00 × 104 N. (a) Is the work done by the engine on the airplane equal to the change in the airplane’s kinetic energy after it travels through some distance through the air? Is mechanical energy conserved? Explain. (b) Find the speed of the airplane after it has traveled 5.00 × 102 m. Assume the airplane is in level flight throughout the motion.

(a)

To determine
Whether the work done by the engine is equal to the change in kinetic energy of the airplane after the plane travels in the air through some distance and is mechanical energy is conserved.

Explanation

No. The change in kinetic energy of the airplane will be equal to the net work done by all the forces acting on the airplane. There are two forces acting on the airplane here. One is engine’s thrust energy and the other one is the resistive force exerted by the air on the plane. Since the sir resistance on the plane is opposite to the motion of the plane, the force due to air resistance is negative.

Therefore, the network done on the plane will be less than the positive force exerted by the engine’s thrust energy...

(b)

To determine
The speed of the airplane.

Still sussing out bartleby?

Check out a sample textbook solution.

See a sample solution

The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started 