1. Displacement, speed, velocity, acceleration and momentum
Physics of Motion:
Displacement, speed, velocity, acceleration and momentum

2. Displacement-time graphs
Y axis is displacement/distance (position)
X axis is time
Slope of a line at any point is the speed (velocity).
Slope = (y2 – y1)/(x2 – x1)
Positive slope of straight line indicates constant, positive speed
Negative slope indicates movement in opposite direction
Slope of zero (flat line) indicates object at rest
An increasing slope (curve upward) indicates positive acceleration (speeding up)
A decreasing slope indicates negative acceleration (slowing down)

3. Distance-time graph summary

4. Velocity-time graphs Y axis is speed or velocity X axis is time
Y value of zero means object is at rest.
Slope of a line at any point is the acceleration.
Positive slope of straight line indicates constant, positive acceleration
Negative slope indicates negative acceleration (slowing down)
Slope of zero (flat line) no acceleration, so constant velocity

5. Speed-time graph summary

6. Movement in two dimensions
Vectors (in two dimensions) can be broken down into vector components of each dimension.
Each component vector (for say, velocity) behaves and can be analyzed independently.
Plain English: the vertical velocity is not influenced by the horizontal velocity, and vice versa.
Velocity of cannon ball
Vy (vertical velocity)
Vx (horizontal velocity)

7. To break a vector down into its dimensional components…
Draw a horizontal vector pointing in the same direction of the original vector
Draw a vertical vector pointing in the same direction
Make a right triangle. The original vector is the hypotenuse

8. How to calculate the magnitude of the component vectors
To find vx (horizontal vector), multiply the magnitude of the original vector by the cosine of the angle of the vector.
𝑣𝑥=𝑣∗𝑐𝑜𝑠𝜃
To find vy (vertical component), multiply the magnitude of the original vector by the sine of the angle of the vector
𝑣𝑦=𝑣∗𝑠𝑖𝑛𝜃
V = 10 m/s
Vy = 10 m/s * sin (30°)
θ = 30°
Vx = 10 m/s * cos (30°)