2nd Grade Science
Forces at Work
Unit 2
Unit 2: Forces at Work
Unit 2: Forces at Work
Forces
Forces
What happens when you push on a toy car? How about when your team pulls the hardest in tug of war? The reason the car rolls or your team wins is because you applied a force - a push or a pull.
Let's get started! Watch this quick intro in which I go over the basics of pushes and pulls!
Let's get started! Watch this quick intro in which I go over the basics of pushes and pulls!
In order to put an object that is not moving (still) into motion, we have to apply a force to it. Examples of forces are pushes, pulls, and friction.
In order to put an object that is not moving (still) into motion, we have to apply a force to it. Examples of forces are pushes, pulls, and friction.
A push is a force we apply to move an object AWAY from us.
A push is a force we apply to move an object AWAY from us.
A pull is a force we apply to move an object CLOSER to us.
A pull is a force we apply to move an object CLOSER to us.
When his foot hits the soccer ball in order to move it, is it a push, or a pull?
When his foot hits the soccer ball in order to move it, is it a push, or a pull?
Push; he is trying to move the ball away from him, in a certain direction.
When he catches the ball, is it a push, or a pull?
When he catches the ball, is it a push, or a pull?
Pull; when he catches the ball, he is pulling it towards him.
Speed
Speed
When we apply a force to an object, like a push or a pull, we change its speed - how fast it is going. What matters most here is how "hard" or "soft" you push or pull. The harder you do it, the more force you apply, and the more you change the object's speed. For example, when this frog pushes the ball harder, it rolls faster!
When we apply a force to an object, like a push or a pull, we change its speed - how fast it is going. What matters most here is how "hard" or "soft" you push or pull. The harder you do it, the more force you apply, and the more you change the object's speed. For example, when this frog pushes the ball harder, it rolls faster!
Direction
Direction
Pushes and pulls have directions, too! In order to get things moving the right way, we have to aim our pushes and pulls in the right direction. If I'm playing basketball and the hoop is in front of me and higher up, I need to push the ball forward and up! When you push or pull, you can also change the direction of an object! If a ball is rolling to the right, pushing on it to the left can change its direction towards the left.
Pushes and pulls have directions, too! In order to get things moving the right way, we have to aim our pushes and pulls in the right direction. If I'm playing basketball and the hoop is in front of me and higher up, I need to push the ball forward and up! When you push or pull, you can also change the direction of an object! If a ball is rolling to the right, pushing on it to the left can change its direction towards the left.
Play this game to practice pushes and try to get Fetch's plushie into the target! Press "PLAY". Look at how far away the target is and aim your shot in that direction. Don't do it too hard or too soft...be careful!
Play this game to practice pushes and try to get Fetch's plushie into the target! Press "PLAY". Look at how far away the target is and aim your shot in that direction. Don't do it too hard or too soft...be careful!
Friction
Friction
Rub your hands together. Do you feel your hands getting warm? This is because of the force of friction. Friction is a force that makes things heat up. This force only exists when objects rub against each other. Have you ever gotten "carpet burn" by rubbing your hand against the carpet? Your hand rubbing against the carpet created heat, and made your hand warm. Friction doesn't normally make objects start moving, but it can make them stop.
Rub your hands together. Do you feel your hands getting warm? This is because of the force of friction. Friction is a force that makes things heat up. This force only exists when objects rub against each other. Have you ever gotten "carpet burn" by rubbing your hand against the carpet? Your hand rubbing against the carpet created heat, and made your hand warm. Friction doesn't normally make objects start moving, but it can make them stop.
Collisions
Collisions
Last thing: when objects collide, or run into each other, they push on each other. An example of this is a car crash - two cars pushing back on each other. Sometimes, when objects collide, they change shape too! Bad car crashes can end up damaging cars because the push from the other car changes its shape.
Last thing: when objects collide, or run into each other, they push on each other. An example of this is a car crash - two cars pushing back on each other. Sometimes, when objects collide, they change shape too! Bad car crashes can end up damaging cars because the push from the other car changes its shape.
