Question

newtons laws of motion review
part a: mass, inertia, weight, and newtons first law of motion

1. which of the following statements are true of inertia? list all that apply.

a. inertia is a force.
b. inertia is a force which keeps stationary objects at rest and moving objects in motion at constant velocity.
c. inertia is a force which brings all objects to a rest position.
d. all objects have inertia.
e. a more massive object has more inertia than a less massive object.
f. fast - moving objects have more inertia than slow - moving objects.
g. an object would not have any inertia in a gravity - free environment (if there is such a place).
h. inertia is the tendency of all objects to resist motion and ultimately stop.
i. in a gravity - free environment (should there be one), a person with a lot of inertia would have the same ability to make a turn as a person with a small amount of inertia.

1. which of the following statements are true of the quantity mass? list all that apply.

a. the mass of an object is dependent upon the value of the acceleration of gravity.
b. the standard metric unit of mass is the kilogram.
c. mass depends on how much stuff is present in an object.
d. the mass of an object is variable and dependent upon its location.
e. an object would have more mass on mount everest than the same object in the middle of lake michigan.
f. people in weight watchers are really concerned about their mass (theyre mass watchers).
g. the mass of an object can be measured in pounds.
h. if all other variables are equal, then an object with a greater mass would have a more difficult time accelerating.
i. if all other variables are equal, then it would require less exerted force to stop a less massive object than to stop a more massive object.
j. the mass of an object is mathematically related to the weight of the object.

Explanation:

• For Inertia (Question 1):
• Inertia is not a force (so A, B, C are wrong). It is a property of matter.
• All objects have inertia (D is correct).
• Inertia depends on mass, more massive objects have more inertia (E is correct).
• Inertia does not depend on speed (F is wrong).
• Inertia is a property of matter and exists regardless of gravity (G is wrong).
• Inertia is the tendency to resist changes in motion (not to ultimately stop, H is wrong).
• In a gravity - free environment, inertia still depends on mass, so a more massive person has more inertia and different turning ability (I is wrong).
• For Mass (Question 2):
• Mass is independent of the acceleration of gravity (A is wrong).
• The standard metric unit of mass is the kilogram (B is correct).
• Mass depends on the amount of matter (stuff) in an object (C is correct).
• Mass is constant and not location - dependent (D, E are wrong).
• Pounds is a unit of force (weight), not mass (G is wrong).
• From \(F = ma\), a more massive object is harder to accelerate (H is correct).
• From \(F = ma\) (or \(a=\frac{F}{m}\)), less massive objects require less force to stop (I is correct).
• Weight \(W=mg\), so mass is mathematically related to weight (\(m = \frac{W}{g}\)) (J is correct).

Answer:

1. D, E
2. B, C, H, I, J