Friction OALH

Do Now

1

After being stretched, springs return to their original shape because they are…

1

Which law states that the extension of a spring is proportional to the weight attached to it?

1

State the pH of an alkali

1

Which technique could be used to separate the different coloured chemicals in a sample of ink?

1

Put the following numbers in order from smallest to largest: 5, 6, 2, -2, -5

1

If something is falling at terminal velocity it will be travelling at a constant speed. What does that tell us about the forces acting on it?

Checking For Understanding

1

Friction is a…

1. Contact force

2. Non-contact force

3. Heated force

1

Friction always acts in the…

1. Same direction to an object’s movement

2. Opposite direction to an object’s surface

3. Opposite direction to an object’s movement

1

Lubricants are used to…

1. Reduce friction

2. Increase friction

3. Keep friction the same

1

Lubricants work by…

1. Acting as a layer between the smooth surfaces which makes it easier for the surfaces to move over each other.

2. Acting as a layer between the rough surfaces which makes it easier for the surfaces to move over each other.

3. Acting as a layer between the rough surfaces which makes it harder for the surfaces to move over each other.

Key Knowledge

1

What type of force is friction?

1

State where friction acts

1

State which direction friction acts

1

How can we reduce friction?

1

Which has more friction a rough surface of a smooth surface

Quick Quiz

1

To reduce friction we use………

1

Friction always acts ……..

1

Friction is an example of a …………

1

Salt is put on icy roads to help melt the ice. Explain why else we might add salt to icy roads.

You do

1

I think that the cyclist is trying to_______ the amount of friction on his bike chain by adding oil (a lubricant) because…

1

State whether the friction between the skater and the ice is high or low. Explain how you know.

1

Explain how the soles of trainers are designed to increase friction between the shoe and the ground.

1

Suggest what might happen if you tried to walk in shoes which didn’t have a special pattern on the soles.

1

You are the manager of Evans Cycles (specialist bike shops). Write a paragraph to explain how you ensure your buyers are safe when cycling.

Plenary

1

Draw one arrow on the diagram to show the direction of the force which prevents the wagon from moving.

1

Is the force which prevents the wagon from moving greater than, equal to or less than the pull of the engine?

1

When the wagon’s brakes are off, the engine pulls the wagon forwards. A frictional force also acts on the wagon. In what direction does the frictional force act?

1

The pull of the engine is 5000 N. When the wagon’s speed is increasing, how large is the frictional force?

zero

between 0 and 5000 N

5000 N

more than 5000 N

1

After a while, the wagon travels at a steady speed. The engine is still pulling with a force of 5000 N.
How large is the frictional force now?

zero

between 0 and 5000 N

5000 N

more than 5000 N

Friction OALH

After being stretched, springs return to their original shape because they are…

Which law states that the extension of a spring is proportional to the weight attached to it?

State the pH of an alkali

Which technique could be used to separate the different coloured chemicals in a sample of ink?

Put the following numbers in order from smallest to largest: 5, 6, 2, -2, -5

If something is falling at terminal velocity it will be travelling at a constant speed. What does that tell us about the forces acting on it?

Friction is a…

Friction always acts in the…

Lubricants are used to…

Lubricants work by…

What type of force is friction?

State where friction acts

State which direction friction acts

How can we reduce friction?

Which has more friction a rough surface of a smooth surface

To reduce friction we use………

Friction always acts ……..

Friction is an example of a …………

Salt is put on icy roads to help melt the ice. Explain why else we might add salt to icy roads.

I think that the cyclist is trying to_______ the amount of friction on his bike chain by adding oil (a lubricant) because…

State whether the friction between the skater and the ice is high or low. Explain how you know.

Explain how the soles of trainers are designed to increase friction between the shoe and the ground.

Suggest what might happen if you tried to walk in shoes which didn’t have a special pattern on the soles.

You are the manager of Evans Cycles (specialist bike shops). Write a paragraph to explain how you ensure your buyers are safe when cycling.

Draw one arrow on the diagram to show the direction of the force which prevents the wagon from moving.

Is the force which prevents the wagon from moving greater than, equal to or less than the pull of the engine?

When the wagon’s brakes are off, the engine pulls the wagon forwards. A frictional force also acts on the wagon. In what direction does the frictional force act?

The pull of the engine is 5000 N. When the wagon’s speed is increasing, how large is the frictional force?

After a while, the wagon travels at a steady speed. The engine is still pulling with a force of 5000 N.How large is the frictional force now?

After being stretched, springs return to their original shape because they are…

Which law states that the extension of a spring is proportional to the weight attached to it?

State the pH of an alkali

Which technique could be used to separate the different coloured chemicals in a sample of ink?

Put the following numbers in order from smallest to largest: 5, 6, 2, -2, -5

If something is falling at terminal velocity it will be travelling at a constant speed. What does that tell us about the forces acting on it?

Friction is a…

Friction always acts in the…

Lubricants are used to…

Lubricants work by…

What type of force is friction?

State where friction acts

State which direction friction acts

How can we reduce friction?

Which has more friction a rough surface of a smooth surface

To reduce friction we use………

Friction always acts ……..

Friction is an example of a …………

Salt is put on icy roads to help melt the ice. Explain why else we might add salt to icy roads.

I think that the cyclist is trying to_______ the amount of friction on his bike chain by adding oil (a lubricant) because…

State whether the friction between the skater and the ice is high or low. Explain how you know.

Explain how the soles of trainers are designed to increase friction between the shoe and the ground.

Suggest what might happen if you tried to walk in shoes which didn’t have a special pattern on the soles.

You are the manager of Evans Cycles (specialist bike shops). Write a paragraph to explain how you ensure your buyers are safe when cycling.

Draw one arrow on the diagram to show the direction of the force which prevents the wagon from moving.

Is the force which prevents the wagon from moving greater than, equal to or less than the pull of the engine?

When the wagon’s brakes are off, the engine pulls the wagon forwards. A frictional force also acts on the wagon. In what direction does the frictional force act?

The pull of the engine is 5000 N. When the wagon’s speed is increasing, how large is the frictional force?

After a while, the wagon travels at a steady speed. The engine is still pulling with a force of 5000 N.How large is the frictional force now?

After a while, the wagon travels at a steady speed. The engine is still pulling with a force of 5000 N.
How large is the frictional force now?

After a while, the wagon travels at a steady speed. The engine is still pulling with a force of 5000 N.
How large is the frictional force now?