AP Physics 1: Review of Universal Gravitation

The video reviews universal gravitation topics for the AP Physics 1 exam, focusing on Newton's universal law of gravitation, the differences between planet-specific and universal gravity equations, and the concept of gravitational fields. It explains how to calculate satellite velocity and discusses gravitational potential energy in both constant and non-constant fields. The lesson concludes with a preview of the next topic, simple harmonic motion.

What does the 'r' represent in Newton's universal law of gravitation?

• The distance between the centers of mass of two objects

• The radius of the Earth

• The diameter of the smaller object

• The radius of the larger object

How is the acceleration due to gravity on Earth calculated using Newton's law?

• By multiplying the mass of the object by the radius of the Earth

• By dividing the mass of the Earth by the distance squared

• By setting the force of gravity equal to the mass times acceleration due to gravity

• By adding the mass of the object to the mass of the Earth

Why can the gravitational field be considered constant locally?

• Because the gravitational field is always constant

• Because the gravitational field lines are parallel

• Because the Earth's radius is much larger than the height

• Because the mass of the Earth is negligible

What is the formula for the tangential velocity of a satellite in orbit?

• The square root of big G times the mass of the satellite divided by r

• The square root of big G times the mass of the Earth divided by r

• The square root of the mass of the Earth times the radius of the satellite

• The square root of big G times the radius of the Earth

What is the key difference between gravitational potential energy in constant and non-constant fields?

• The presence of a negative sign in constant fields

• The use of a squared distance in non-constant fields

• The need to set a zero line in non-constant fields

• The requirement of two masses in constant fields

Why is universal gravitational potential energy always less than or equal to zero?

• Because it uses the mass of only one object

• Because it is set with objects infinitely far apart

• Because it is calculated with a negative sign

• Because it is always positive

What does the equation for gravitational potential energy in a constant field involve?

• Only the mass of the object

• The radius of the Earth

• The mass of the object and the Earth

• Only the mass of the Earth