Universal Law of Gravitation PDF

Universal Law of Gravitation Learning Goals Success Criteria: Recall Newton’s Law of Universal Gravitation. Solve problems involving the magnitude of gravitational force between two masses. Calculate the strength and acceleration due to the gravitational force. Fundamen...

Universal Law of Gravitation Learning Goals Success Criteria: Recall Newton’s Law of Universal Gravitation. Solve problems involving the magnitude of gravitational force between two masses. Calculate the strength and acceleration due to the gravitational force. Fundamentals Anyone recall the four fundamental forces in the universe? Inverse Square Law # THINKING Universal Law of Gravitation DON’T FORGET – EVEN THOUGH THESE WILL TYPICALLY BE USED IN TERMS OF ASTRONOMICAL MASSES AND DISTANCES, THEY MUST BE IN SI UNITS.  Found on page 83 Newton’s process Universal Law of Gravitation Examples Universal Law of Gravitation Questions Extra Information While the force of gravity acts between all masses, it is very weak. – The force becomes significant when at least one of the masses is very large. The universal law of gravitation explains why objects accelerate towards the surface of the Earth, and why planets and moons move in circular orbits. Determine the value for g (Earth) # THINKING Determine the value for g (Earth) # THINKING Note that in this equation we see that the acceleration of a mass m due to Earth’s gravity depends on the Earth’s mass and on its radius. – The acceleration is independent of the mass of the body. The value g = 9.8 m/s 2 is often described as a constant. – This is true only for the specific case when an object is on or near the surface of the Earth. – The value of g changes as an object’s altitude changes. – Also, the acceleration due to gravity on other astronomical bodies differs based on their different masses. CHALLENGE 1 Complete the following table outlining values of ‘g’ at different altitudes: Altitude g Comment (km) (m/s^2) 0 Earth’s surface 8.8 Mount Everest 80 Arbitrary beginning of space 9.21 Mercury capsule orbit altitude 300 Typical space shuttle orbit altitude 0.19 Communications satellite orbit altitude CHALLENGE 2 Complete the following table outlining values of ‘g’ on different celestial bodies: Body Mass Radius g (kg) (km) (m/s^2) Pluto 1,137 1,738 Mars 3.7 Jupiter 71,492 24.8 CHALLENGE 1 Complete the following table outlining values of ‘g’ at different altitudes: Altitude g Comment (km) (m/s^2) 0 9.80 Earth’s surface 8.8 9.77 Mount Everest 80 9.54 Arbitrary beginning of space 200 9.21 Mercury capsule orbit altitude 300 8.94 Typical space shuttle orbit altitude 40,000 0.19 Communications satellite orbit altitude CHALLENGE 2 Complete the following table outlining values of ‘g’ on different celestial bodies: Body Mass Radius g (kg) (km) (m/s^2) Pluto 1,137 0.7 Moon 1,738 1.6 Mars 3,397 3.7 Jupiter 71,492 24.8 Determine the value for g Questions Multi-body Systems So far, this only considers systems with two bodies. Realistically, there’s more than one body pulling on an object being considered. What objects do you think are pulling on you right now? The overall gravitational force will be the vector sum of all the gravitational pulls acting upon a body. # LITERACY Words to define (or research if necessary): Orbit Axis Period Ellipse AU (astronomical units) Satellite Atomi time… Apparent weight to be covered separately