Exploring Pushes and PullsGrade 2

What is energy?

• Energy is the ability to do work. Energy can cause things to move.

• There are different types of energy such as light, heat, sound, and motion.

• We store energy from food in our bodies.

What is force?

• If a force is applied to a stable object, the object moves and changes position.

• Force can be applied from different directions.• The object moves in response to the force.• Work means to apply force to an object over a

distance.

What is friction?

• Friction is produced when two objects come in contact with each other.

• Friction is a force that works against motion.

What is gravity?

• Gravity is a force of attraction that acts on all physical objects.

• Gravity pulls objects to the earth. Objects stay balanced and stable unless we apply force.

• We can apply force to make an object move, but the object will stop moving because of gravity.

What is mass?

• Mass is the amount of matter inside of something.

• Weight is the force exerted on a mass by gravity.

Motion

• Linear motion is motion in straight lines (forward, backward, side to side, up, down).

• Circular motion spins around an axis.• How can we change the motion of an object?

1. We can make it go faster. 2. We can make it slow down. 3. We can change the direction of the motion.

Extension Activity # 1

Simple machineDemonstrate how a pulley works. Stand beneath the teddy bear. The teddy bear is above you. Pull down on the rope to make the teddy bear go up. When the rope goes up, the teddy bear goes down. The pulley is a simple machine that does work by changing direction.

Extension Activity # 2

• Test different balls (glass, wood, plastic, etc.) on a bare ramp to see which one goes the furthest. How was it different from the others?

• Use a balance and gram masses to compare the balls. Did the difference in mass change the results?

• Is there anything else we could do to improve our results? (manipulate slope)