Non-Inertial Frames and Acceleration

Professor Anderson explains the concept of inertial frames, emphasizing that they are frames with constant velocity and zero acceleration. Through an elevator scenario, he illustrates how differing scale readings indicate non-inertial frames. The discussion extends to real-world examples, including Earth's rotation, which introduces centripetal acceleration, making it a non-inertial frame. Despite this, for practical purposes, we often consider it inertial. The session concludes with an invitation for further questions.

What is a key characteristic of an inertial frame?

• It is always moving in a circle.

• It has constant acceleration.

• It has constant velocity.

• It is always stationary.

In the elevator scenario, why is the frame considered non-inertial?

• The scale reads the same as the weight.

• The scale reads more than the weight.

• The elevator is moving with constant velocity.

• The elevator is at rest.

What would the scale read if the elevator was in an inertial frame?

• 110 Newtons

• 90 Newtons

• 100 Newtons

• 120 Newtons

What is the acceleration in an inertial frame?

• It is always positive.

• It is equal to zero.

• It is equal to gravity.

• It is always negative.

When sitting in a chair, why might you be considered in an inertial frame?

• Because you are moving in a circle.

• Because you are accelerating.

• Because your velocity is changing.

• Because your acceleration is zero.

How does Earth's rotation affect our inertial frame status?

• It makes us always in an inertial frame.

• It causes centripetal acceleration.

• It has no effect on our frame status.

• It stops us from moving in a circle.

Why is the Earth's rotation considered a non-inertial frame?

• Because it is not moving.

• Because it involves centripetal acceleration.

• Because it has constant velocity.

• Because it is stationary.

What is the approximation made about our inertial frame on Earth?

• We are never in an inertial frame.

• We are approximately in an inertial frame.

• We are always in a non-inertial frame.

• We are always accelerating.

What is the effect of centripetal acceleration on our frame status?

• It makes us stationary.

• It makes us move in a straight line.

• It makes us in a non-inertial frame.

• It has no effect.

What is the technical status of our frame due to Earth's rotation?

• Stationary

• Non-inertial

• Inertial

• Constant velocity