| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.12 |
| Score | 0% | 62% |
The force exerted on an object due to gravity is called:
mass |
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weight |
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potential energy |
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density |
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.
When it comes to force, mass and acceleration have what kind of relationship?
exponential |
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logarithmic |
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inverse |
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linear |
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.
Which of the following is the formula for gravitational potential energy?
\(PE = { 1 \over 2} mv^2\) |
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\(PE = { 1 \over 2} mg^2\) |
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\(PE = mgh\) |
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\(PE = mg^2h\) |
Gravitational potential energy is energy by virtue of gravity. The higher an object is raised above a surface the greater the distance it must fall to reach that surface and the more velocity it will build as it falls. For gravitational potential energy, PE = mgh where m is mass (kilograms), h is height (meters), and g is acceleration due to gravity which is a constant (9.8 m/s2).
Which of the following will increase the mechanical advantage of a second-class lever?
decrease the length of the lever |
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move the object being lifted farther away from the fulcrum |
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move the fulcrum between the force and the object being lifted |
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move the object being lifted closer to the fulcrum |
A second-class lever is used to increase force on an object in the same direction as the force is applied. This lever requires a smaller force to lift a larger load but the force must be applied over a greater distance. The fulcrum is placed at one end of the lever and mechanical advantage increases as the object being lifted is moved closer to the fulcrum or the length of the lever is increased. An example of a second-class lever is a wheelbarrow.
Boyle's law defines the relationship between pressure and volume as:
\(\frac{P_1}{P_2} = \frac{V_2}{V_1}\) |
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\({P_1}{P_2} = {V_1}{V_2}\) |
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\(\frac{P_1}{P_2} = {V_1}{V_2}\) |
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\(\frac{P_1}{P_2} = \frac{V_1}{V_2}\) |
Boyle's law states that "for a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional". Expressed as a formula, that's \(\frac{P_1}{P_2} = \frac{V_2}{V_1}\)