Your Results | Global Average | |
---|---|---|
Questions | 5 | 5 |
Correct | 0 | 3.03 |
Score | 0% | 61% |
Depending on where you apply effort and resistance, the wheel and axle can multiply:
force or speed |
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power or distance |
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force or distance |
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speed or power |
If you apply the resistance to the axle and the effort to the wheel, the wheel and axle will multiply force and if you apply the resistance to the wheel and the effort to the axle, it will multiply speed.
For any given surface, the coefficient of static friction is ___________ the coefficient of kinetic friction.
opposite |
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equal to |
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higher than |
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lower than |
For any given surface, the coefficient of static friction is higher than the coefficient of kinetic friction. More force is required to initally get an object moving than is required to keep it moving. Additionally, static friction only arises in response to an attempt to move an object (overcome the normal force between it and the surface).
Which of the following statements about drag is false?
slower objects experience more drag than faster objects |
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the amount of drag depends on the speed of an object |
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drag occurs during movement through a fluid |
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the amount of drag depends on the shape of an object |
Drag is friction that opposes movement through a fluid like liquid or air. The amount of drag depends on the shape and speed of the object with slower objects experiencing less drag than faster objects and more aerodynamic objects experiencing less drag than those with a large leading surface area.
The work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. This defines which of the following?
Pascal's law |
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conservation of mechanical energy |
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work-energy theorem |
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mechanical advantage |
The work-energy theorem states that the work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. Simply put, work imparts kinetic energy to the matter upon which the work is being done.
A ramp is an example of which kind of simple machine?
first-class lever |
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inclined plane |
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none of these |
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wedge |
An inclined plane is a simple machine that reduces the force needed to raise an object to a certain height. Work equals force x distance and, by increasing the distance that the object travels, an inclined plane reduces the force necessary to raise it to a particular height. In this case, the mechanical advantage is to make the task easier. An example of an inclined plane is a ramp.