Chapter 4 Quiz Jessica Brandon

How do we describe motion?

·      With speed, velocity, and acceleration. Speed equals the distance divide time. To get velocity you do speed plus the direction. Acceleration is the change in velocity. Momentum is also used to describe motion which is mass times velocity. Force causes a change in momentum, which means acceleration.

How is mass different from weight?

·      The difference is mass is equal to the quantity of water and weight is the force acting on mass. Objects are weightless when in free-fall.

How did Newton change our view of the universe?

·      Newton discovered the laws of motion and gravitation. He also realized these same law of physics were identical to the universe and on earth

What are Newton's three laws of motion?

·      Newton’s three laws… His first law was that objects move at a constant velocity if no net force is acting. His second law is that force equals the mass times the acceleration. Newton’s third law was for every force there is an equal and opposite reaction force.

What keeps a planet rotating and orbiting the Sun?

·      What keeps a planet rotating and orbiting the sun is the law of conservation of angular momentum.

Where do objects get their energy?

·      Objects get their energy by conservation of energy. Which is the energy cannot be treated or destroyed it can only be transformed from one type to another. Energy comes in three basic types.

What determines the strength of gravity?

·      Directly proportional to the product of the masses. Inversely proportional to the square of the separation.

How does Newton's law of gravity extend Kepler's laws?

·      His law applies to other objects, not just the planets. His laws include unbound orbit shapes parabola and hyperbola. We can no measure the mass of other systems.

How do gravity and energy allow us to understand orbits?

·      Gravity is what determines the orbits. Orbiting objects cannot change its orbit without energy being transferred.

How does gravity cause tides?

·      What gravity does to the tides is stretches earth along earths-moon line because the near side is pulled harder then the far side.