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Science Test
Science Test on Friday
Term | Definition |
---|---|
Force | -Any push or pull on an object -Has strength and direction -Measured with a springscale -Unit is Newtons (N) -Types include applied force, air, gravity, magnetic, electric, etc. |
Net Force | -Total overall forces acting upon an object -Forces in the same direction add up -Forces in opposite directions subtract |
Measuring force with a spring scale | 1) Zero out spring scale 2) Determine scale 3) Take measurement OPTIONAL- 4) Team check |
Force diagram | Shows all forces acting on an object |
Unbalanced Force | -A nonzero net force that causes an object to accelerate -If an object is not moving, it will move -If an object is moving, it will speed up, slow down, or turn |
Balanced Force | -A zero net force that does not cause an object to accelerate -If an object is not moving, then it will not move -It an object is moving, then it will move at a constant velocity |
Mass | The amount of matter in an object |
Weight | The force of gravity acting upon an object |
Formula for weight | W=mg NOTE: On earth, gravity is 9.8 |
Does gravity change? | The gravitational force affecting your and other objects changes depending on mass and distance |
What is Newton's Law of Universal Gravitation? | The force of gravity acts between all the objects in the universe |
What does the strength of gravity depend on? | The masses of objects and the distance between their centers |
Formula for gravity between two objects | Fg= m1*m3/d^2 |
What is Fa? | Applied force |
What is Ff | Frictional force |
Friction | A force that opposes motion and slows down moving objects |
What does friction depend on? | 1) Texture (rougher surfaces require more force) 2) Normal force |
What are the forms of friction? | 1) Static (stationary) 2) Kinetic (moving) |
What are the types of friction? | 1) Sliding (one surface slides over another) 2) Rollings (one surface rolls over another) 3) Fluid (When one surface moves on/through a fluid) |
What is fluid friction? | A force that occurs between a moving object and a fluid (liquid or gas) that slows the object down |
What does fluid friction depend on? | 1) Shape (Bulkier, non-streamlined objects tend to create more friction) 2) Speed (The faster something is going, the more friction there is) |
What is free fall? | When the only force acting upon an object is gravity. |
Which way will objects fall when they are in free fall? | In the direction of the net force (usually down) |
What is terminal velocity and when does it occur? | When the downward force of gravity is cancelled out by the upward force of air resistance. The object no longer accelerates, it moves at a constant speed. |
What is a projectile? | An object that is in free fall but moving horizontally at the same time. It could be thrown, kicked, or shot. The motion looks similar to that of a parabola. |