Unit 2 - Kinematics

Question 1

Mechanics

Answer 1

the study of motion and forces
kinematics = description of motion
dynamics = study of the forces that cause changes in motion

Question 2

Vectors and scalars

Answer 2

scalar quantities have magnitude (size), including a unit, but no direction
vector quantities have both magnitude and direction

Question 3

Position and displacement

Answer 3

displacement describes both the magnitude and direction of a change in position
a number line can be used

Question 4

Speed and velocity

Answer 4

theses are the rates at which distance and displacement change
displacement and velocity have the same direction
preferred unit is m/s

Question 5

Calculating velocity from graphs

Answer 5

speed is the slope of a distance-time graph, and velocity is the slope of a displacement-time graph
uniform motion = uniform velocity, when both speed and direction remain constant

Question 6

Calculating average velocity from graphs

Answer 6

calculate the slope of the secant by using any two pairs of points
the average velocity is the slope of the line joining the two points on the curve

Question 7

Calculating instantaneous velocity from graphs

Answer 7

this is calculated for a moment in a time, when the change in time is closest to 0
instantaneous velocity is the slope of the tangent to the curve

Question 8

Acceleration

Answer 8

the rate at which velocity changes
it could be a change in speed, direction, or both speed and direction
acceleration is always a vector quantity

Question 9

Calculating acceleration from graphs

Answer 9

uniform acceleration occurs when a velocity changes by an equal amount each second
acceleration is the slope of a velocity-time graph

Question 10

Changing acceleration

Answer 10

for instantaneous acceleration, calculate the slope of the tangent
for average acceleration, calculate the slope of the secant

Question 11

Displacement from a velocity-time graph

Answer 11

displacement is the area of a velocity-time graph

Question 12

Relative motion problems

Answer 12

relative motion = the motion of one object with respect to another which may be moving or stationary
frame of reference = the point of view from which one observes motion

Question 13

Projectile motion

Answer 13

projectile = object that has been launched and which doesn’t have its own propulsion system
a projectile follows a parabolic path
the range is the horizontal distance it gets
no horizontal acceleration
for vertical motion, the acceleration formulas must be used
horizontal and vertical motion must be calculated separately and then combined to produce an answer