Motion

• Equation for speed

  Speed= distance * time
• Equation for acceleration

  Acceleration= change in velocity/ time
• What is a scalar?

  Scalar quantities are just a number (magnitude)
• What is a vector?

  A magnitude with a direction.
• Is speed a scalar or vector?

  Scalar
• Is velocity a scalar or vector?

  Vector
• What is displacement?

  How far an object has moved from its original position. It is a vector
• What are scale drawings?

  They are used to find the resultant displacement of two vectors at right angles using pythagorem theorem.
• What does the gradient show in a distance-time graph?

  It shows speed. The steeper the gradient, the faster the speed. If you calculate the gradient you will get the speed
• If the line in a distance-time graph is curved, it shows acceleration or deceleration.
• Calculating the gradient of a velocity-time graph calculates the acceleration.
• Calculating the area under a velocity-time graph calculates the distance travelled. Simply break the shape into triangles or rectangles.
• Label the diagram

  A) accelerating

  B) constant speed

  C) decelerating

  D) stationary

  
• Moving objects have kinetic energy (stored in their kinetic store)
• What is the equation for kinetic energy?

  Kinetic energy= 0.5 * mass * speed^2
• The unit for KE is joules (J).
• This equation allows you to calculate the distance travelled for objects accelerating=

  Final velocity^2 - Initial velocity^2 = 2 * acceleration * distance
• Final velocity= √2 * acceleration * distance + initial velocity^2

  (everything is in the square root)
• Initial velocity= √final velocity^2 - 2 * acceleration * distance

  (everything is in the square root)
• What is the formula to calculate speed using distance and time?

  speed = $\frac{distance}{time}$