Chelsea Esposito Quiz

Chelsea Esposito

Quiz 3

1. We describe motion by stating that speed = distance / time. Speed and
direction make up velocity, while change in velocity is acceleration.
Momentum = mass x velocity, and force causes change in momentum,
producing acceleration.
2. Mass = the quantity of matter and weight = the force acting on mass. Objects
are weightless during free fall.
3. Newton changed our views of the universe by realizing the same physical
laws that operate on Earth also operate in the “heavens”. He discovered laws
of motion and gravity. He also did experiments with light, and invented the
first reflecting telescope, and calculus.
4. Newton’s first law of motion is that an object moves at constant velocity
unless a net force acts to change its speed or direction. Newton’s second law
of motion is Force = mass × acceleration. And Newton’s third law is for every
force, there is always an equal and opposite reaction force.
5. The reason planets orbit and rotate around the sun is because the angular
momentum of an object cannot change unless an external twisting force is
acting on it
6. Objects get their energy from another object, or it can change in form.
7. The Universal Law of Gravitation determines the strength of gravity. The
first part is that every mass attracts every other mass. The second part is that
attraction is directly proportional to the product of their masses. And part
three is that attraction is inversely proportional to the square of the distance
between their centers.
8. Newton’s law of gravity helps to extend Kepler’s laws because Kepler’s first
two laws apply to all orbiting objects, not just planets.
9. Total orbital energy stays constant if there is no external force. Orbits cannot
change spontaneously.
10. Gravity causes tides because the moon’s gravity pulls harder on the near
side of Earth rather than on the far side. The difference in the Moon’s
gravitational pull stretches Earth.