Exam 1

Question 1

How many cm are in 1 in?

Answer 1

2.540

Question 2

How many feet are in 1 mile?

Answer 2

5280.

Question 3

How many days are in a year?

Answer 3

365.24

Question 4

_______ are quantities that have size, but do not have direction

Answer 4

scalars

Question 5

_______ are quantities with both size and direction

Answer 5

vectors

Question 6

A vector is know only if both ____ and _____ are known.

Answer 6

size

direction

Question 7

How do we represent vectors graphically?

Answer 7

with arrows

Question 8

_____ of the arrow shows the vector’s size while the _____ of the arrow shows the vectors direction

Answer 8

length

direction

Question 9

Vectors _____ fixed in space.

Answer 9

are not

Question 10

How can you obtain the resultant vector?

Answer 10

adding any number of vectors by arranging them tip to tail

Question 11

For a vector, what does the angle indicate?

Answer 11

direction

Question 12

For a vector, what does length represent?

Answer 12

magnitude

Question 13

For graphical vector addition, order _____ matter

Answer 13

doesn’t; therefore A + B = B+A

Question 14

What does multiplying vectors by scalars change?

Answer 14

the length and/or direction of the vector

Question 15

What is vector subtraction adding simply?

Answer 15

adding the negative of the vector

Question 16

What is the sum of the two component vectors?

Answer 16

the original vector

Question 17

How do you find Ax and Ay when theta is measured from the positive x-axis to the y-axis?

Answer 17

Ax = A cos(theta)
Ay = A sin(theta)

Question 18

What does theta equal?

Answer 18

theta = arctan(Ay/Ax)

Question 19

What is the unit vector for the x-direction?

Answer 19

i^

Question 20

What is the unit vector in the y-direction?

Answer 20

j^

Question 21

What is the unit vector in the z-direction?

Answer 21

k^

Question 22

What is the scalar product/dot product defined as?

Answer 22

A . B = ABcos φ

where φ is the smallest angle between the two vectors drawn with their tails at a common point

Question 23

What is the vector product/cross product’s magnitude defined as?

Answer 23

A x B = AB sinφ

….and a direction defined by the right-hand rule

Question 24

What units define position?

Answer 24

meters-(m) SI
feet-(ft)
miles-(mi)
etc.

Question 25

What units define velocity?

Answer 25

m/s

Question 26

For displacement and average velocity, what must be defined?

Answer 26

a coordinate system

Question 27

What is instantaneous velocity?

Answer 27

the limit of the average velocity as delta t ----> 0

Question 28

For displacement along the x-axis, what does the objects average x-velocity equal?

Answer 28

the slope of a line connecting the corresponding points on a graph of position(x) vs time(t)

Question 29

Like velocity, acceleration is a ______

Answer 29

vector

Question 30

What is the 1st kinematic equation?

Answer 30

vx = vox + axt

Question 31

What is the second kinematic equation?

Answer 31

x = xo + voxt + (1/2)axt^2

Question 32

What is the third kinematic equation?

Answer 32

v^2x = v^2ox + 2ax(x - xo)

Question 33

What is the fourth kinematic equation?

Answer 33

(x - xo) = (vox + vx/2)t

Question 34

What is the position vector?

Answer 34

r = xi^ + yj^ + zk^

Question 35

The average velocity between two point will have the same ______ as the _______

Answer 35

direction | displacement

Question 36

What is displacement?

Answer 36

delta r

Question 37

What is magnitude?

Answer 37

speed at that instant

Question 38

What is direction?

Answer 38

the direction a particle is moving at that instant --- always tangent!

Question 39

How can you break up instantaneous velocity up into its components?

Answer 39

vx = dx/dt; vy = dy/dt; vz = dz/dt

Question 40

A nonzero acceleration vectors results in

Answer 40

a change in the magnitude AND/OR direction of the velocity

Question 41

ANY particle following a curved path is

Answer 41

accelerating

Question 42

What happens to a particle when acceleration is parallel to the particles velocity?

Answer 42

changes magnitude but not direction of velocity | particles moves in a straight line with changing speed

Question 43

What happens to a particle when acceleration is perpendicular to a particles velocity?

Answer 43

changes direction but not magnitude of velocity | particles follows a curved path at constant speed

Question 44

What is a projectile?

Answer 44

any body given an initial velocity that then follows a trajectory determined by the effects of gravity and air resistance

Question 45

Are projectile motion problems 2D or 3D?

Answer 45

2D because gravity cannot push sideways

Question 46

X and Y motion are ________ and can be considered ______

Answer 46

independent | separately

Question 47

A rock dropped from a 5-m height accelerates at 9.80 m/s2 and strikes the ground 1 s later. If the rock is dropped from a height of 2.5 m, its acceleration of fall is

Answer 47

the same

Question 48

If an object moves with constant acceleration, its velocity must

Answer 48

change by the same amount each second

Question 49

If you whirl a rock at the end of a string, it follows a circular path. If the string breaks, the tendency of the rock is to

Answer 49

follow a straight-line path

Question 50

The speedometer of an automobile reads

Answer 50

instantaneous speed

Question 51

If you set the cruise control of your car to a certain speed and take a turn, the speed of the car will remain the same. Is the car accelerating?

Answer 51

Yes

Question 52

A pilot drops a package from a plane flying horizontally at a constant speed. Neglecting air resistance, when the package hits the ground the horizontal location of the plane will

Answer 52

be over the package

Question 53

If A and B are nonzero vectors for which A · B = 0, it must follow that

Answer 53

| A × B | = AB

Question 54

A quarterback throws a long touchdown pass. The ball leaves his hand at a height of 2.0 m, but the wide receiver must slide to make the catch barely above the ground. Which statement about the football's speed is false?

Answer 54

The ball leaves the quarterback's hand at the same total speed as it has when it is caught