Mass

An object weighs 42.53 newtons. What is its mass if a gravitometer indicates that g = 9.83 m/s^2 ?

4.33 kg

accuracy

The measure of exactness to the true and actual value.

What is mass?

the amount of matter in an object

A person's weight changes at a higher elevation because _____.

the effect of gravity decreases as the person gets further away from Earth

What happens if the mass is doubled or tripled?

If one mass is doubled, the force is doubled; if one mass is tripled, the force is tripled.

The space shuttle is descending through the earth's atmosphere. How is the force of gravity affected?

It will increase with descent.

Is mass universal?

Yes. The quality of matter called mass is universal. No matter where in the universe a kilogram of matter exists, it will always be a kilogram.

Mass dos not depend upon:

distance from the earth, moon, or sun as weight does. It depends only upon the make-up of the object, and it is a property of that object. We measure samples of matter by comparing them with standard units of mass.

If the combined mass of two objects increases by a factor of 10, how will F g be affected?

increased by 10 times

The standard unit of mass is the:

kilogram

At the top of a high mountain, the weight of an object is:

less than at sea level

Gravity causes:

objects to attract one another

What does a balance measure?

A balance measures the quantity of matter independent of its form or shape. This quantity of matter is called mass.

Gravity

A force that pulls objects toward the center of earth and gives weight to objects.

Units of mass

A gram is a very small unit of mass. A larger unit of mass is the kilogram (kg). A kilogram equals about two and one-fifth pounds and is the standard mass unit in the international system. One gram (g) is one-thousandth (0.001) of a kilogram (kg). One kilogram contains one thousand (1,000) grams.

Mass

A measure of the amount of matter in an object

What is the magnitude of the earth's gravity?

Among the planets of our solar system, the magnitude of the earth's gravity is selected to represent 1.0

What happens when the distance between the masses gets altered?

As the distance between the masses increases, the force of gravity decreases by the distance squared. If the distance is doubled, the force decreases to 1/4 the original force; if the distance is tripled, the force decreases to 1/9 the original force. This is why various planets have different magnitudes of gravitational force. The primary factor is their differences in mass.

Formula for gravitational force

F=Gm1m2/r^2

An object has a mass of 15 kg. On Planet X, the object weighs 126 N. The force of gravity on Planet X is:

8.4 m/s^2

On Earth, the average measurement of g is:

9.8 m/s^2

2,000 grams is equal to:

2 kilograms

On the surface of the earth, a kilogram weighs approximately:

2 pounds

In a lab, the mass of object A is 2.5 kg. Object A weighs:

24.5 N

0.001 kilogram equals to what?

1 gram = 1,000 milligrams

1 cm^3 = ?

1 mL = 1g

1 kilogram equals to what?

1,000 grams (g) = 1,000,000 milligrams (mg)

A glass jar contains 1 kg of liquid. This is the same as:

1,000 mL, 1,000 g, 1,000 cm 3

What happens as the mass of either object increases?

As the mass of either object increases, the force of gravity increases by the same proportion.

What would effect the weight of a person on Earth?

Earth is not a perfect sphere so there are different distances to the center of Earth's mass. Variations in the density of the earth's crust affect the gravitational constant at different locations on Earth's surface.

Why is gravity on the surface of Jupiter is only two-and-a-half times the gravity on the surface of Earth?

Even though Jupiter has many times the mass of Earth. The answer is that the surface of Jupiter is farther from the center of Jupiter than Earth's surface is from its center. Therefore, while the gravity of Jupiter is greater than Earth's because of Jupiter's greater mass, the increase is relatively small because of increased distance from the center. You must always measure the distance from the center of a mass, not from the surface.

The mathematical statement that shows the relationship between gravity and mass

Fg ~ m/d^2

How is gravity measured?

Gravity is measured in meters per second squared (m/s2). The standard unit of force is the newton (N). Since weight is a measure of the force of gravity on an amount of mass, it is measured in newtons when mass is measured in kilograms.

Balance is used to determine:

Mass

Equal-arm balances are devices that are used to measure:

Mass

What happens once the mass is defined?

Once the unit of mass is defined, samples of matter can be compared to the unit and thus measured. Comparing a sample of matter to the standard unit of mass, or to its subdivision the gram, can be done on an equal-arm balance.

kilogram (kg)

Standard metric unit of mass; mass of 1 L of water; symbolized by kg.

precision

The consistency with which the same result is achieved when an object is repeatedly measured or an experiment is repeatedly performed.

Why is the equal-arm balance the most accurate measurement of mass?

The formula for weight can be rearranged to calculate mass. However, the accuracy of this calculation is dependent on the accuracy of the measurement of weight. For this reason, the equal-arm balance remains the most accurate measurement of mass.

How about other planets?

The gravitational forces of other planets, depending on their relative masses, will be greater or less than that of Earth. Mercury's force of gravity (relative to Earth) is .38. Jupiter is 2.5 on this relative scale.

The Mass of Water

The metric units of volume and mass are related to water. One cubic centimeter of water equals one milliliter of water, and the mass of each volume is one gram. A small box that is one cubic centimeter in size holds exactly one milliliter of water, and that one milliliter of water has a mass of one gram. A liter of water contains 1,000 cm3, or 1,000 mL of water. Therefore, a liter of water contains 1,000 grams, or one kilogram.

If a person travels to the moon which measurement will change?

The person's weight

The equation used to describe weight is:

W = mg; the W stands of weight, the M stands for mass, and the G stands for Gravity

Weight

Weight is a measure of the pull or attraction between two objects.

The weight of an object on the surface of a planet is determined by:

the radius of the planet as well as its mass. The magnitude of gravitational force is inversely proportional to the square of the distance between the objects. As you ascend above the surface, the force of gravity (weight) decreases as the distance to the center of mass increases.

The force of gravity on Planet Y is 5.3 m/s 2 . The force of gravity on Planet Z is 6.2 m/s 2 . A 10 kg object would:

weigh less on Planet Y than on Planet Z