Astronomy 1021 Chapter Notes - Chapter 4: Kelvin, Orbital Speed, Projectile Motion

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Reynold Silber

Document Summary

Velocity: speed and direction (ex: 10m/s, due east) Ex: 0 to 100 km/h in 4 seconds. Mass: the amount of matter in an object. On earth, we often think about this in terms of an object"s weight. Not quite correct- mass and weight are different but related things. 1kg on earth = 1kg on moon. Acceleration due to gravity is independent of the mass of object. Newton"s second law: f=mg (force = mass x acceleration) Inertia: resistance of any physical object to any change in its state of motion: this is why any ball dropped from the top of a building will fall at the same rate. Force: interaction between objects that changes speed, direction or shape. Net force: sum of all forces acting on an object. If net force is mon-zero, get change of momentum (usually an acceleration) Realized same physical laws that operate on earth also operate in heavens.