Amber Reed Quiz

Quiz

How do we describe motion?
Motion can be defined by its components of speed, velocity and accelration.  Speed is the rate at which object moves speed=distance/time (units of m/s)
example:speed of 10 m/s. Velocity is speed and direction, an example of is would be10 m/s,due east. Acceleration is any change in velocity; units of speed/time (m/s to the 2nd power).

How is mass different from weight?
Mass is the amount of matter in an object, while weight is the force that acts on an object. Essentially you are weightless and free. 

How did Newton change our view of the universe?
Newton realized the same physical laws that operate on Earth also operate in the heavens; one universe. Newton also discovered  laws of motion and gravity. His experiments with light;first reflecting telescope,calculus helped as well.

What are Newton's three laws of motion?
Newton's first law of motion is an object moves at constant velocity unless a new force acts to change its speed or direction. Newton's second law of motion is that
force=mass x acceleration. Lastly, Newton's third law is for every force, there is always an equal and opposite reaction force.


What keeps a planet rotating and orbiting the Sun?
Conservation of momentum which is the total momentum of interacting objects cannot change unless an external force s acting on them. It also deals with interacting objects exchange momentum through equal ad opposite forces.
Angular momentum =mass x velocity x radius is a facet of conservation momentum. The angular momentum of an object cannot change unless an external twisting force (torque) is acting on it.

Where do objects get their energy?
The fact that energy makes matter move and is conserved but it can transfer form one object to another change in form.

What determines the strength of gravity?
The universal law of gravitation every mass attracts every other mass. Attraction is directly proportional to the product of their masses. Attraction also inversely proportional to the square of the distance between their centers.

How does Newton's law of gravity extend Kepler's laws?
Kepler's first two laws apply to all orbiting object not just planets; ellipses are not the only orbital paths.  Orbits can be bound(ellipses),unbound(parabola and hyperbola). Newton generalized Kepler's third law; if a small object orbits a larger one and you measure the orbiting objects.

How do gravity and energy allow us to understand orbits?
Total orbital energy (gravitational+ kinetic) stays constant if there is no external force;orbits cannot change spontaneously.

How does gravity cause tides?
The moon's gravity pulls harder of near side of Earth rather than on far side. This is because the difference i the moon's gravitational pull stretched Earth and size of tide depends on the phase of the moon.


Amber Reed