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Friction
questions
Question | Answer |
---|---|
Name the four types of friction. | static,sliding, rolling, and fluid |
How does static friction occur? | Two surfaces that are not moving past each other |
Give an example of static friction | A house sitting on land answers may vary |
What is the purpose of aerodynamic design? | It offers the least resistance to air flow |
Why do golf balls have dimples in them? | The dimples offer the least resistance to air flow and allows the ball to travel faster and straighter. |
A car turns right without slowing down. Is there an unbalanced force present? | Yes |
A spacecraft moves in one direction at a constant speed. Is there an unbalanced force present? | No |
A cyclist coasts downhill, going faster and faster. Is there an unbalanced force present? | Yes |
What is the SI unit for acceleration? | meters per second squared |
Acceleration is caused by a__________. | Force |
Is friction a force? | Yes |
How does friction act on any object? | Friction always acts in a direction to oppose motion |
When two solid objects come into contact, the friction is mainly due to what? | Due to irregularities in the two surfaces |
Is air resistance fluid friction? | Yes |
If the net force is zero, what is the acceleration? | Zero |
Zookeepers life a stretcher that holds a sedated lion. The total mass of the lion and stretcher is 175 kg, and the lion's upward acceleration is 0.657 meters per second squared. What is the unbalanced force? | 115 N |
A baseball accelerates downward at 9.8 meters per second squared. If the gravitational force acting on the baseball is 1.4 N, what is the baseball's mass? | 0.14 kg |
A sailboat and its crew have a combined mass of 655 kg. If the sailboat experiences an unbalanced force of 895 N pushing it forward, what is the sailboat's acceleration? | 1.37 meters per second squared |
Why do trucks have large caps? | Trucks can go faster because air flows over the caps instead of hitting the truck directly |
Name some good things and some bad things about friction. | answers will vary |