Kinematics and Dynamics

Question 1

vector quantity has…

Answer 1

magnitude and direction

Question 2

scalar quantity has…

Answer 2

only magnitude

Question 3

dot product

Answer 3

A . B = |A| |B| cos θ

Question 4

cross product

Answer 4

A x B = |A| |B| sin θ

Question 5

vector of position, only final and initial taken into account

Answer 5

displacement

Question 6

scalar of position, considers path taken

Answer 6

distance

Question 7

velocity (v)

Answer 7

vector,

v = ∆X/∆t (m/s)

Question 8

acceleration (a)

Answer 8

vector,

a = ∆v/∆t (m/s^2)

Question 9

SI unit of force (F)

Answer 9

vector,

Newtons (N) = kg*m/s^2

Question 10

gravitational force between two objects

Answer 10

Fg = (Gm1m2)/r^2

where:
G = 6.67E-11 N*m^2/kg^2

Question 11

force that opposes movement between stationary object and surface

Answer 11

static friction (fs)

Question 12

static friction (fs)

Answer 12

fs ≤ μs*N
μs = coefficient of static friction (depends on two materials)
N = normal force, component force perpendicular to plane of contact

Question 13

force that opposes movement between sliding object and surface

Answer 13

kinetic friction (fk)

Question 14

kinetic friction (fk)

Answer 14

fk = μk*N
μk = coefficient of kinetic friction (depends on two materials)

Question 15

amount of matter in an object (scalar)

Answer 15

mass

Question 16

measure of gravitational force on an objects mass (vector)

Answer 16

weight (W)

Question 17

weight (W)

Answer 17

W = m*g
m = mass
g (Fg) = 9.8 m/s^2 (approximately 10) (on earth)

Question 18

center of mass/gravity of uniform object

Answer 18

x = ( (m1x1) + (m2x2) + (m3x3) + …) / (m1 + m2 + m3 + …)

same for y and z, just replace x

Question 19

Newton’s laws

Answer 19

F = m*a   ,   Fab = -Fba
F = force
m = mass
a = acceleration
Fab = force from a to b
-Fba = equal and opposite reaction

Question 20

equations of linear motion

Answer 20

x = v*t
x = v(o)*t + (1/2) a*t^2
v = v(o) + a*t
v^2 = v(o)^2 + 2*a*x

where v(o) = velocity initial

Question 21

forces that cause an object to move in a circular path, object has a tendency to break out of circular path

Answer 21

circular motion

Question 22

keeps object from breaking out of circular motion path, always points radially inward

Answer 22

centripetal force

Question 23

generated by centripetal force

Answer 23

centripetal acceleration

Question 24

centripetal acceleration (Fc)

Answer 24

Fc = m*v^2 / r

Question 25

happens when force applied to object that causes it to rotate

Answer 25

rotational motion

Question 26

fixed point object rotates around

Answer 26

fulcrum

Question 27

generated by application of force at some distance; clockwise is positive, counterclockwise is negative

Answer 27

torque (𝜏)

Question 28

distance between applied force and fulcrum

Answer 28

lever arm

Question 29

torque (𝜏)

Answer 29

``` 𝜏 = r*F = r*F sin θ r = length of lever arm F = magnitude of force θ = angle between lever arm and force vectors ```

Question 30

state of the absence of any net forces acting on an object

Answer 30

translational equilibrium

Question 31

state of the absence of any net torques acting on an object

Answer 31

rotational equilibrium