Gravitational Force

First we received our Newton's 2nd Law Investigation Labs, which we discussed why the %error was so high. We discovered that because we completely ignored the role of friction in the lab, it caused the over all result of the lab to be inaccurate. Mr. Banow than explained that we are to comment on his blog post and come up with a new and improved lab that will account for the friction.

We than began looking at Gravitational Force and learned three new definitions.

• Force of Gravity- objects are pulled toward the Earth no matter their location on or above the Earth's surface.



• Gravitational Field Constant- value is 9.8N/Kg and is represented by the letter g. This value is very close to being accurate anywhere on or near the Earth's surface.



• Gravitational Field Strength- the force of gravity is not the same everywhere therefore it is defined by the amount of force acting on a mass of 1Kg. For example there are different values on different planets.

Formula: F=mg

Example: The force of gravity on a 300.0Kg spacecraft on the moon is 489N. What is the gravitational field strength on the moon?

m=300.0Kg F=489N g=?

F=mg ----> g=F/m ----> g=489N/300.0Kg = 1.63N/Kg or 1.63m/s^2

Lastly we reviewed that mass and weight ARE DIFFERENT. Mass refers to the amount of matter in an object and stays the same no matter where it is. Weight describes the force of gravity on an object and changes depending on the gravitational field.

Jolene is next.