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Section 1-3 Test
Scence Unit 1 Chapter 1 Section 1-3 TEST
Question | Answer |
---|---|
Speed | Speed is the distance of an object traveled divided by the total time |
Velocity | Velocity is the speed of an object in a particular direction |
Acceleration | The rate at which velocity changes over time an object accelerates if it's speed, direction, or both change. |
Motion | Change in position relative to a reference point |
Two factors that determine speed? | Distance and time |
Force | A push or pull exerted on an object |
Net Force | The combination of all of the forces acting on an object |
Friction | A force that opposes motion between two surfaces that are in contact |
Balance Force | When the forces on an object produce a net force of 0N, the forces are balanced. No change in motion. |
Unbalanced Force | When the net force of an object is greater than 0N, the forces on the object is unbalanced. A change in motion. |
How is friction helpful? | Friction between your feet and the floor helps you walk. Rock climbers needs friction between their feet and the rock to prevent slipping. |
How is friction harmful? | When sliding an object more friction makes it more difficult to move. Friction in a car engine can wear out engine parts. |
Ways to increase friction? | Make surfaces rougher, Slide an object instead of rolling it, and increase the force pushing two surfaces together. |
Ways to decrease friction? | Make surfaces smoother,reduce force pushing two surfaces together, roll an object instead of sliding it, and use a lubricant (oil/grease/wax). Wax on skis makes it go faster. |
What are two factors that determine the amount friction? | The amount of force pushing two surfaces together, more force= more friction. The roughness of the surface, rougher surface= more friction. |
To calculate a net force: When forces are in opposite directions YOU | Subtract the smaller from the larger. |
To calculate a net force: When forces are in the same direction YOU | Add them together. |
Static Friction | Friction created between two surfaces that are not moving. As soon as an object starts moving, static friction is changed to Kinetic Friction. |
Kinetic Friction: Rolling Friction? | Rolling Friction is usually smaller than sliding friction. It's easier to pull a child in a wagon than to slide a child. |
Kinetic Friction: Sliding Friction? | Sliding an object usually creates more friction than rolling. |
Formula for Calculating Average Speed? | Average Speed= total distance over total time |
To make a velocity you? | Add a direction |
When one speed changes it is called? | Acceleration Speed up= positive acceleration Slow down= negative acceleration or deceleration or changes directions |
Reference Point | Non moving/moving objects. For determining motion, the surface of the earth is a common reference point. |