Physics Concepts in Circular Motion

This video, led by Dede Messer, covers AP Physics practice questions on gravitation and simple harmonic motion. It includes calculations of gravitational acceleration on Planet X, astronaut acceleration in orbit, satellite speed, and the radius of a new planet. The video also explores comet speed and kinetic energy in elliptical orbits, spring systems, and potential energy functions. The session concludes with deriving differential equations for simple harmonic oscillators.

What are the two main topics covered in this AP Physics session?

• Optics and Waves

• Electromagnetism and Thermodynamics

• Quantum Mechanics and Relativity

• Gravitation and Simple Harmonic Motion

If a planet has a mass one-tenth that of Earth and a diameter half that of Earth, what is the acceleration due to gravity on its surface?

• 8 m/s²

• 6 m/s²

• 2 m/s²

• 4 m/s²

An astronaut is 300 km above Earth's surface. What is their acceleration in a circular orbit?

• 9 m/s²

• 3 m/s²

• 6 m/s²

• 0 m/s²

A satellite moves from a distance R to 2R from a planet's center. What is the new speed required for a circular orbit?

• V₀/2

• V₀/√2

• 2V₀

• V₀

In an elliptical orbit, if position 1 is ten times farther from the Sun than position 2, what is the speed ratio V1/V2?

• 1/20

• 1/5

• 1/10

• 1/2

At which position is the kinetic energy of a comet in an elliptical orbit around the Sun the greatest?

• At the farthest point from the Sun

• At the closest point to the Sun

• At the midpoint of the orbit

• Kinetic energy is constant

What is the spring constant if a 0.4 kg object attached to a spring has a period of 1 second?

• 16 N/m

• 8 N/m

• 20 N/m

• 12 N/m

What is the potential energy function for a conservative force given by F = -kx³?

• 1/2 kx²

• 1/4 kx⁴

• kx

• 1/3 kx³

Which equation describes Newton's second law for a simple harmonic oscillator?

• F = ma

• F = kx

• F = mv²/r

• F = -kx

What is the relationship between force and potential energy in a conservative system?

• Force is the negative derivative of potential energy

• Force is the integral of potential energy

• Force is the derivative of potential energy

• Force is the square of potential energy