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Review Force and Motion-1

When this traffic jam starts moving, the cars will be able to speed up faster than the big trucks. Why?

  1. The cars have more powerful engines.

    No. The trucks have more powerful engines than the cars do.
  2. The cars have tires with more friction.

    No. The truck tires are larger, which means they have more contact with the ground, and more friction.
  3. The cars weigh less.

    Yes! The heavier an object is (the more mass it has), the more force it takes to move it. The trucks weigh a lot more than the cars, so it takes much more energy to get them moving.
  4. The cars are more streamlined

    No. A streamlined shape helps when the cars are moving quickly, but does not do much as they are starting up.

Click to see which state standards this question tests, and which of my videos, experiments, and other resources support that topic.


SC.5.P.13.3 Investigate and describe that the more mass an object has, the less effect a given force will have on the object's motion.


UT.3.III.2.b Compare and chart the relative effects of a force of the same strength on objects of different weight (e.g., the breeze from a fan will move a piece of paper but may not move a piece of cardboard).
Floating Cups video, checked
Water in a Glass, part 2 video, checked
Water in a Glass, part 3 video, checked
Water in a Glass, part 1 video, checked
High Bounce video, checked
Review Force and Motion-1 practice
Review Force and Motion-2 practice


MS-PS2-2 Plan an investigation to provide evidence that the change in an object’s motion depends on the sum of the forces on the object and the mass of the object.