motion

• What defines scalar quantities?

  They have magnitude but no direction
• Why does mass not have a direction?

  It only has magnitude
• What is the unit of energy?

  Joules
• What is potential difference a measure of?

  Energy per unit charge
• What is power defined as?

  Energy per unit time
• What characterizes a vector quantity?

  It has both magnitude and direction
• How is a vector typically expressed?

  By an arrow
• What does displacement represent?

  Distance traveled in a particular direction
• What is the difference between distance and displacement?

  Distance is path length; displacement is direction
• What happens to displacement if you return to the starting point?

  Displacement is zero
• How do you add two parallel vectors?

  • Add the quantities if in the same direction
  • Subtract if in opposite directions
• What is the first step in adding two perpendicular vectors?

  Move them to be tip to tail
• How do you find the magnitude of a resultant vector?

  Use Pythagoras's theorem
• What is the formula for Pythagoras's theorem?

  $c^2 =$$a^2 +$$b^2$
• What is the resultant force of a 4.0 N and a 3.0 N vector?

  5.0 N
• How do you determine the direction of a resultant vector?

  Use trigonometry
• What is the tangent function used for in vector analysis?

  To find angles in right triangles
• What is the formula for the tangent of an angle?

  $\tan(\theta) =$$\frac{\text{opposite}}{\text{adjacent}}$
• How do you resolve a vector into components?

  Use sine and cosine functions
• What does the vertical component of a vector represent?

  Force acting vertically
• What is the vertical component of a 5 N force at 30 degrees?

  $2.5 \text{ N}$
• What topic is being revised in this video?

  Motion topic
• What is the difference between distance and displacement?

  Distance is a scalar; displacement is a vector
• What is the horizontal component of a 5 N force at 30 degrees?

  $4.33 \text{ N}$
• How is distance defined?

  Total length of the path traveled
• How do you find the horizontal component of a vector?

  Multiply hypotenuse by cosine of angle
• How is displacement defined?

  Distance in a particular direction
• What is the vertical component of a 7 N force at 20 degrees?

  $7.0 \times \sin(20^\circ)$
• What is average speed?

  Total distance divided by total time
• What is average velocity?

  Total displacement divided by total time
• What is the horizontal component of a 7 N force at 20 degrees?

  $7.0 \times \cos(20^\circ)$
• What happens to displacement if an object returns to its original position?

  Displacement is zero
• What are the key differences between scalar and vector quantities?

  • Scalar quantities: magnitude only, no direction
  • Vector quantities: both magnitude and direction
• What is instantaneous velocity?

  Velocity at a particular point in time
• How is instantaneous velocity calculated from a graph?

  It is the gradient of the tangent
• What are the steps to resolve a vector into components?

  1. Identify the angle and magnitude
  2. Use sine for the opposite component
  3. Use cosine for the adjacent component
• What is the formula for velocity in terms of displacement?

  Velocity is $\frac{\Delta s}{\Delta t}$
• What is acceleration defined as?

  Rate of change of velocity
• What is the direction of the vector mentioned?

  20 degrees to the vertical
• What are the units for acceleration?

  Meters per second squared