| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.53 |
| Score | 0% | 71% |
Which of these is the formula for force?
F = a/m |
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F = am2 |
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F = m/a |
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F = ma |
Newton's Second Law of Motion states that "The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object." This Law describes the linear relationship between mass and acceleration when it comes to force and leads to the formula F = ma or force equals mass multiplied by rate of acceleration.
A ramp is an example of which kind of simple machine?
first-class lever |
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wedge |
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inclined plane |
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none of these |
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.
Normal force is generally equal to the __________ of an object.
density |
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weight |
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mass |
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coefficient of friction |
Normal force arises on a flat horizontal surface in response to an object's weight pressing it down. Consequently, normal force is generally equal to the object's weight.
The force exerted on an object due to gravity is called:
potential energy |
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density |
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weight |
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mass |
Mass is an intrinsic property of matter and does not vary. Weight is the force exerted on the mass of an object due to gravity and a specific case of Newton's Second Law of Motion. Replace force with weight and acceleration with acceleration due to gravity on Earth (g) and the result is the formula for weight: W = mg or, substituting for g, weight equals mass multiplied by 9.8 m/s2.
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?
mechanical advantage |
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Pascal's law |
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conservation of mechanical energy |
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work-energy theorem |
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.