Subscribe

3rd grade · Science · Unit 3 of 12

Speed & Motion

Fast and slow, why things keep moving, and what changes how quickly motion changes.

What your child practices

Practices speed as the distance an object travels in a certain time, inertia (objects keep doing what they are doing until a force acts), and how mass and force affect how quickly motion changes.

Texas Essential Knowledge and Skills (TEKS) teks student expectation: 3.7(B); 3.8(B) · how pushes and pulls change motion, and how speed relates to mechanical energy

How we explain it

Children can open this short lesson before they practice.

  1. Speed is how far something travels in a certain time.
  2. Things keep doing what they are doing until a force acts on them.
  3. Friction slows things down. Rough grass has more friction than smooth ice.

Example: A runner goes 10 km in one hour. A walker goes 5 km. Who is faster? Both took one hour. 10 km is farther than 5 km. Answer: the runner

Speed & Motion in Texas

In the Texas Essential Knowledge and Skills (TEKS), this is unit 3 of 12 in 3rd grade Science, after Pushes, Pulls & Forces and before How Plants Grow & Change.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: Texas Education Agency (TEA)

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    A snail goes slowly because it…

    • travels a short distance in a long time
    • has no body
    • is heavy like a rock

  2. Question 2

    In a fair test of speed, you should keep the track…

    • different each time
    • wet for one car only
    • the same for each car

  3. Question 3

    Which unit could measure the time something takes?

    • seconds
    • meters
    • liters

  4. Question 4

    Inertia means objects…

    • always speed up
    • always stop
    • keep doing what they are doing until a force changes it

  5. Question 5

    A ball rolls on grass and stops sooner than on ice. This is because of…

    • friction
    • gravity only
    • magnets

  6. Question 6

    Which object is moving at constant speed?

    • A ball being dropped and speeding up
    • An elevator moving 1 floor every 2 seconds the whole way
    • A car braking

More 3rd grade