Chapter 1 Physics
The highest waterfall in the world is Angel Falls in Venezula, with a total drop of 979 m. Write the height of the falls in cm using scientific notation.
9.79*10^4 cm
The tail of a vector is fixed to the origin of an x, y axis system. Originally the vector points along the +x axis and has a magnitude of 12 units. As time passes, the vector rotates counterclockwise. For which of the following rotational angles is the x component of the vector equal to zero?
90, and 270 degrees
What is a vector quantity?
A quantity that deals inherently with both magnitude and direction.
Which of the following displacement vectors (if any) are equal? (Several choices may be correct.)
A- 100m 30 degrees north of east D- 100m 60 degrees east of north
What was the original definition for second?
According to the average time for the earth to rotate once about the axis, one day being set equal to 86400 seconds. Earths rotation was chosen because it was consistent
What are scalar components?
Ax and Ay. Are positive or negative numbers (with units).
What is the international definition of meter?
Became the distance between two marks on a bar of platinum-iridium alloy
In the equation y=cnat2 you wish to determine the integer value (1, 2, etc.) of the exponent n. The dimensions of y, a, and t are known. It is also known that c has no dimensions. Can dimensional analysis be used to determine n?
No, because since c has no dimensions, then c raised to any exponent n also has no dimensions. Dimensional analysis can't give any information regarding quantities that have no dimensions.
Two vectors with the same magnitude are necessarily equal.
No, two vectors that have the same magnitude aren't equal if they have different directions.
What does base in base SI units refer to?
Refers to the fact that these units are used along with various laws to define additional units for other important physical quanitities, such as force and energy
What kind of values represent magnitude?
Solely positive values, or zero. Negative value is never an option.
What do the arrows represent in vector quantities?
The direction of the arrow gives the direction of the vector.
What units are associated for British Engineering system?
The gravitational version uses the foot (ft), the slug (sl), and the second
Two vectors A→ and B→ are added together to give a resultant vector R→: R→=A→+B→. The magnitudes of A→ and B→ are 3 m and 8 m, respectively, but the vectors can have any orientation. What is (a) the maximum possible value and (b) the minimum possible value for the magnitude of R→?
The maximum is 11m (8+3), you can add because they point in the same direction. The minimum is 8+-3=5m where it demonstrates if the vectors point in the opposite direction.
Two vectors, A→ and B→, have vector components that are shown (to the same scale) in the drawing. The resultant vector is labeled R→. Which drawing shows the correct vector sum of A→+B→?
The one with positive x axis and and y component negative.
What is the improved definition of a second?
The time needed for 9192631770 waves to occur.
Vectors A→, B→, and C→ satisfy the vector equation A→+B→=C→, and their magnitudes are related by the scalar equation A2+B2=C2. How is vector A→ oriented with respect to vector B→?
The two vectors are perpendicular
Vectors A→, B→, and C→ satisfy the vector equation A→+B→=C→, and their magnitudes are related by the scalar equation A+B=C. How is vector A→ oriented with respect to vector B→?
Their directions are the same.
In preparation for this question, review Conceptual Example 7. Vectors A→ and B→ satisfy the vector equation A→+B→=0. How does the magnitude and direction of B→ compare to the magnitude and direction of A→?
Their magnitudes are the same, but their directions aren't
Three or more vectors with unequal magnitudes can be added together so their sum is zero.
True
What are the base SI units?
Units for length, mass, and time
What are derived units?
Units for other physical quantities, combination of base units.
What is dimensional analysis?
Used to check mathematical relations for the consistency of their dimensions.
Each trigonometric function can be written as the ratio of the lengths of two sides of a right triangle. Do the lengths of the sides of the triangle have to have the same units?
Yes
Is it possible for two quantities to have the same dimensions but different units?
Yes
The magnitude of a vector has doubled, its direction remaining the same. Can you conclude that the magnitude of each component of the vector has doubled?
Yes, multiplying the magnitude of a vector changes the magnitudes of the vector's components by the same factor.
What are the units associated for the CGS system?
centimeter (cm), gram (g), and second for length, mass, and time
What is magnitude?
measure of size.
In the SI system, what are the units of measurement for length, mass, and time?
meters, kilograms, and seconds.
What is a resultant vector?
the sum of two or more vectors. Denoted by R.
What is a scalar quantity?
Is one that can be described with a single number. Is described but ts size.
What does the length of the arrow indicate?
Is proportional to the magnitude of the vecotr.
What is the fundamental distinction between scalars and vectors?
Is the characteristic of direction.
What is a dimension?
Is used to refer to the physical nature of a quantity and the type of unit used to specify it.
What are SI units stand for and what are the units associated?
Le Systeme International d'Unites By international agreement, this system employs the meter (m) as a unit of length, kilogram (kg) as the unit of mass, and second (s) as the unit of time.
Can the Pythagorean theorem relationship be applied to the three sides of any triangle?
No
Is it possible for two quantities to have the same units but different dimensions?
No
You can always add two numbers that have the same units (such as 6 meters + 3 meters). Can you always add two numbers that have the same dimensions, such as two numbers that have the dimensions of length [L]?
No
What are vector components?
In two dimensions, the components of a vector A are two perpendicular vectors Ax and Ay that are parallel to the x and y axes, respectively, and add together vectorially according to A= Ax + Ay.
What is mass?
Indicates the tendency of the object to continue in motion with a constant velocity
What is kilogram?
Is defined to be the mass of a standard cylinder of platinum-iridium alloy
Two nonzero perpendicular vectors can be added together so their sum is zero?
False
What are the three contributors to physics mentioned?
Galileo Galilei Isaac newton James Clerk Maxwell
Which of the following statements, if any involves a vector? ( Several choices may be correct.)
I walked 2 miles due north along the beach. i jumped off a cliff and hit the water traveling straight down at a speed of 17 miles per hour.
What was the first initial definition of meter?
Meter was defined in terms of the distance measured along the earth's surface between the north pole and the equator.
A vector has a component of zero along the x axis of a certain axis system. Does this vector necessarily have a component of zero along the x axis of another (rotated) axis system?
No
