Year 10 Science Work Pack Phase V 10 Science... · 2020-06-24 · 10 Phase IV work pack Questions answered with full working out or in full sentences on paper All lessons on VLE

Year 10 Science

Ark Globe Academy Remote Learning Pack

Phase V Monday 29 June - Friday 10 July

You should spend 1 hour completing each session.

Please look carefully at the on-line support available to you on the Student VLE

Session Title Work to be completed

Resource provided

Outcome On-Line Support

1 Vectors and scalars

Task 1 (optional) Task 2 (compulsory)

See Session 1 Phase IV work pack

Questions answered with full working out or in full sentences on paper

Yr 10 Scalars and vectors lesson

2 Vectors and scalars – practice questions

Answer all questions



Yr 10 Scalars and vectors lesson

3 Forces between objects




Yr 10 Forces between objects lesson

4 Forces between objects – practice questions




Yr 10 Forces between objects lesson

5 Resultant forces Task 1 (optional) Task 2 (compulsory)



Yr 10 Resultant forces lesson

6 Resultant forces – practice questions




Yr 10 Resultant forces lesson

7 Centre of mass Task 1 (optional) Task 2 (compulsory)



Yr 10 Centre of mass lesson

8 Centre of mass – practice questions




Yr 10 Centre of mass lesson

9 Drawing scale diagrams




Yr 10 Drawing scale diagrams lesson

10 Summary questions




All lessons on VLE

Session 1: Vectors and scalars

Task 1: If you have internet access, review the ppt Yr 10 Vectors and scalars lesson on the VLE.

Task 2: Read through the following information and complete all highlighted questions on paper or in an exercise book.

1) Activate prior knowledge: What are forces?

All matter in the universe interacts with other matter. These interactions are due to forces.

In 1 minute, write down everything you can remember about forces.

Did you get any of the following points?

• The unit of force is the newton (N). • Forces are interactions between pairs of objects – and for this reason forces are always

found in pairs. It is impossible to find a single force on its own. • Forces are pushes or pulls: They have the effect of changing an object’s motion (e.g.

accelerating or decelerating it), or changing its shape if it is not free to move. • Forces are have a magnitude (size) and a direction. • Some forces can act across empty space whereas others require the objects to “touch” –

these are known as “non-contact” and “contact” forces respectively.

2) Scalar and vector quantities

A physical quantity is something that can be measured. Scalar and vector quantities are physical quantities.

A scalar quantity has magnitude (size) but no direction. Some examples of scalar quantities include:

• temperature, e.g. 10 degrees Celsius (°C) • distance, e.g. 19 metres (m) • speed, e.g. 8 metres per second (m/s) • density, e.g. 1,500 kilograms per metre cubed (kg/m³)

A vector quantity has magnitude and direction. Some examples of vector quantities include:

• force, e.g. 20 newtons (N) to the left • displacement, e.g. 50 kilometres (km) east • velocity, e.g. 11 metres per second (m/s) upwards

3) How do we represent vector quantities?

Any vector quantity can be represented by an arrow:

• The direction of the arrow shoes the direction of the vector quantity. • The length of the arrow represents the magnitude of the vector quantity.

Because a force has a magnitude and direction, it is a vector quantity and can be represented on a diagram by an arrow. See the below image showing the force of the hammer on a nail.

Answer the following questions in your books:

1) Which of the following examples are scalar quantities? Which are vector quantities?

a) acceleration, e.g. 9.8 metres per second squared (m/s²) downwards b) mass, e.g. 5 kilograms (kg) c) energy, e.g. 2,000 joules (J) d) momentum, e.g. 250 kilogram metres per second (kg m/s) south west

2) What is the difference between a scalar quantity and a vector quantity?

3) How are vector quantities represented?

Session 2: Vectors and scalars – practice questions

How to complete the following session:

1) Read through the information provided. 2) Use the information and your work from Session 1 to help you answer the questions. 3) Watch the supporting resources on the VLE if you have access.

Q1)

Why are forces vector quantities and not scalar quantities?

Q2)

The image below shows the route from home to school for a student who has to catch a bus to school. The bus has to travel down a road and pick up students along the way.

The distance travelled by the student on the bus is much greater than the direct distance from the students’ home to the school. Distance without change of direction is called displacement. Put simply, displacement is distance in a certain direction.

a) What type of physical quantity is represented by the arrow? Explain your answer.

b) What does the arrow tell us about this physical quantity?

c) What is the difference between distance and displacement?

Session 3: Forces between objects

Task 1: If you have internet access, review the ppt Yr 10 Forces between objects lesson on the VLE.


1) Activate prior knowledge of forces from KS3

Forces can be contact forces or non-contact forces. Contact forces occur when an object is supported by or strikes another object. For example friction is a contact force because it occurs when tyres of a car make contact with the road surface. Non-contact forces act between two objects that are not physically touching each other.

Can you remember which type of the force each of the following are?

Note: Remember that particles in the air and water are examples of objects!

a) Magnetic force b) Weight (Force of gravity) c) Air resistance d) Water resistance

2) Newton’s Third Law – Equal and opposite forces

Forces are interactions between pairs of objects – and for this reason forces are always found in pairs. This law states that when two objects interact with each other, they exert equal and opposite forces on each other.

Example 2: Consider an apple falling from a tree. The Earth pulls on the apple with a force of 1.5N. What’s surprising is that the apple is also pulling on the Earth with a force of 1.5N.

Example 1: When you pull on a rope, the rope pulls on you with a force of the same magnitude and opposite direction.

Wait, what? You might think that because the rope isn’t moving or alive, it can’t be pulling – but this is wrong. If we imagine pulling on a spring, we can easily accept that the spring pulls back on us. The atoms in a rope and any other object act like springs – if we pull on them they pull back!

Answer in your book:

a) What is Newton’s third law? b) State whether the forces in the above examples are contact or non-contact forces. c) A woman leans on a wall with a force of 20 N. What magnitude (size) of force does the wall

apply on the woman? Explain your answer.

3) More interactions between pairs of objects:

On a very rainy day, this car became stuck in the mud. A farmer comes along with his tractor to help. The farmer attaches a rope to the car. At any stage, the force of the rope on the car is equal and opposite to the force of the car on the rope. The arrows on the diagram below show this.

So how does the tractor manage to pull the car out of the mud?

The force of the mud on the tractor needs to be greater than the force of mud on the car (see image below). However these two forces are not equal and opposite to each other. So how does Newton’s third law apply here?

The equal and opposite force to the force of the mud on the tractor is the force of the tractor on the mud (see image below).

Answer in your books:

a) What is the equal and opposite force to the force of mud on the car (see above example)? b) Forces are always interactions between how many objects? c) What is a contact force? d) What is a non-contact force?

Session 4: Forces between object – practice questions


1) Read through the information provided, including the worked example. 2) Use the information and your work from Session 3 to help you answer the questions. 3) Watch the supporting resources on the VLE if you have access.

Q1)

Copy the diagrams showing the gravitational forces between two objects. Use Newton’s third law to add the second force in the interaction. (See the examples in Session 3 if you get stuck).

a) Diagram showing the gravitational forces between Earth (object 1) and the pear (object 2).

b) Diagram showing the forces between the bauble and the string.

c) Diagram showing the forces between water and a ship.

d) Diagram showing the forces between a person and a wall.

Q2)

The diagram below shows an empty cargo ship. It is not moving.

a) The water exerts a force on the ship. In which direction does this force act?

The diagram below shows the same cargo ship. This time it has a full load of cargo.

b) How does the force exerted by the water on the ship change as the ship is loaded?

Optional extension: Why has the force exerted by the water changed?

Session 5: Resultant forces

Task 1: If you have internet access, review the ppt Yr 10 Resultant forces lesson on the VLE.


1) What is a resultant force?

You developed your knowledge of resultant forces in the Phase IV work pack. Here’s a reminder:

• A single object will often have more than one force acting on it. • Because forces are vectors, we can add them together as vectors to find the resultant force. • If the forces are acting in the same direction then we add them together. • If they are in opposite directions then we subtract them.

What is the resultant force on each of these two rectangular objects?

2) Newton’s first law

This law states that if the forces acting on an object are balanced (equal and opposite), the resultant force on the object is zero. If the resultant force is zero then an object is at rest (stationary) or moving at a constant velocity.

a) Describe the motion of the object below. Explain your answer.

b) Is the resultant force on the below object zero? Explain your answer

Object 1 Object 2

3) Force diagrams

When an object is acted on by more than one force, you can draw a free-body force diagram to work out the resultant force on an object. The free-body force diagram shows the forces acting on an object without any other objects or forces shown.

Answer the questions:

a) What is Newton’s first law? b) What is the resultant force on an object when it is moving at a constant velocity? c) Why is the below diagram not a free-body force diagram?

Optional extension (Higher): Draw free-body force diagrams for the following objects.

Session 6: Resultant forces – practice questions


1) Use the information and your work from Session 5 to help you answer the questions. 2) Watch the supporting resources on the VLE if you have access.

Q1)

Find the resultant force on the following objects:

Q2)

A fisherman pulls a boat towards land. The forces acting on the boat are shown in Diagram 1.

The fisherman exerts a force of 300 N on the boat. The sea exerts a resistive force of 250 N on the boat.

a) Describe the motion of the boat. You need to mention the resultant force and whether the boat is accelerating or decelerating.

When the boat reaches land, the resistive force increases to 300 N. The fisherman continues to exert a force of 300 N.

b) Describe the motion of the boat. c) Explain your answer to part (b).

Optional extension (Higher): Calculate the resultant force and draw the free-body force diagrams for the following objects:

Session 7: Centre of mass

Task 1: If you have internet access, review the ppt Yr 10 Centre of mass lesson on the VLE.


Racing cars are designed to keep the car and its weight as near to the ground as possible. Otherwise, the car would overturn when going round corners at high speeds. Therefore, mechanical engineers working on the car design need to know its centre of mass.

1) What is the centre of mass of an object?

In physics we often draw diagrams in order to solve problems. We need to know the point in an object that is “in the middle” with regard to its mass. We call this point the centre of mass. In the shapes below, the centre of mass is marked with a red dot.

The weight of an object is considered to act through its centre of mass. This idea is very useful to designers and engineers. Race car mechanical engineers can make sure that the car is low to the ground at its centre of mass.

Put simply, the centre of mass of an object is the point at which its mass can be thought of as being concentrated.

Copy the following objects and their marked centres of mass. Add an arrow to each to show where the object’s weight acts.

Centre of mass Weight acting through centre of mass

2) How do you find the centre of mass?

The centre of mass is the point about which an object will balance if you try to rest it on your fingertip. Try this with your ruler! Or if you hang an object, for example a picture frame from a nail, the centre of mass will hang directly below the nail.

3) Where is the centre of mass of a symmetrical object?

For a flat object that is symmetrical, its centre of mass is along the axis of symmetry. If the object has more than one axis of symmetry, its centre of mass is where the axes of symmetry meet. If you can find an A4 piece of paper, try finding the centre of mass. Use the image below to help you.

4) Where is the centre of mass of a suspended object?

If you attach an object to a piece of string and hang it from the ceiling, it will come to rest with its centre of mass directly below the point at which the string is attached to the ceiling (its point of suspension). We say that the object is in equilibrium which means it is at rest.

Answer the following questions:

1. What acts through an object’s centre of mass? 2. Why do we need to know an object’s “centre of mass”? 3. An object has more than one line of symmetry. Where would you find the centre of mass? 4. You hang a stuffed teddy bear from its ear. It is attached to the ceiling by a piece of string.

How would you find out its centre of mass?

Session 8: Centre of mass – practice questions


1) Read through the information including the worked example. 2) Use the information and your work from Session 7 to help you answer the questions. 3) Watch the supporting resources on the VLE if you have access.

Q1)

Sketch each of the objects and mark its centre of mass. Add an arrow to show where the object’s weight acts.

Q2)

The image below shows a child’s mobile. The mobile hangs from point P on the ceiling of the child’s bedroom.

A student has used a letter X to mark what they think is the position of the centre of mass of the mobile. Explain why the student is incorrect and describe where the centre of mass should be.

X

Q3) a) The diagram shows a rectangle made out of a sheet of cardboard. Copy the diagram

and draw an X on the diagram so that the centre of the X is at the centre of mass of the rectangle.

b) The drawing shows a car tyre. Where is the centre of mass on the tyre?

c) Explain your answer to b).

Session 9: Drawing scale diagrams

Task 1: If you have internet access, review the ppt Yr 10 Drawing scale diagrams lesson on the VLE.

You could also watch the first minute of this video on Youtube: https://youtu.be/U8z8WFhOQ_Y

If you continue to watch the entire Youtube video then this will develop your knowledge of vector diagrams further. However it is not compulsory.


1) Representing forces using scale diagrams

We use scale diagrams when we want to show more than one force acting on an object. To show both forces – and their relative magnitude (size) – we should use a scale.

A scale is defined as a system or series of marks used for measuring or registering. An example of scale is what someone would use to figure out the length of something.

Worked example:

A force of 4N drives a cyclist forwards to the north. A gust of wind is blowing to the east with a force of 3N.

This image shows the forces acting on the cyclist.

On this second diagram, the cyclist is represented by the little orange dot.

The force of 4N is represented by a 4cm arrow. The force of 3N is represented by a 3cm arrow.

A scale has been used here to show the different magnitude of each force. The scale is: 1N = 1cm

Answer the following questions:

The cyclist goes out for another ride on a different day. This time a force of 7N drives the cyclist in a south direction and a gust of wind blows to the west with a force of 5 N.

a) Look at the diagrams below. Which shows the correct scale diagram of the forces acting on the cyclist when the scale is 1N = 1cm.

b) Explain your answer.

Diagram A Diagram B

c) Sketch an 8 x 8 grid like the below, or use squared paper in your Maths book. d) Copy the force diagram below showing a small object acted on by a horizontal force, A, of

magnitude 3N. e) This object is also acted on by another horizontal force, B, of magnitude 3N, which acts in

the opposite direction to A. Add force B to your diagram.

Optional extension: What is the resultant force on the object in your diagram? What does the force diagram tell you about the motion of the object?

1cm

A = 3N

Session 10: Summary questions


• Use the information and your work from this work pack to help you answer the questions. • Watch the supporting resources on the VLE if you have access.

Equations you may need for the following questions (covered in previous work packs):

Speed (m/s) = distance (m) ÷ time (s)

Acceleration (m/s2) = velocity (m/s) ÷ time (s)

Resultant force (N) = mass (kg) x acceleration (m/s2)

Weight (N) = mass (kg) x gravitational field strength (N/kg)

Momentum (kg m/s) = Mass (kg) × velocity (m/s)

Q1)

a) Complete the following sentences:

Force has both magnitude and direction, so is a _____________________ quantity.

A quantity with magnitude only is a _____________________ quantity.

b) Which of these is a scalar quantity? Select one.

o Displacement o Force o Distance o Velocity

Q2)

a) The diagram shows a lampshade hanging from the ceiling. Sketch the diagram and draw an X on the diagram so that the centre of the X marks the centre of the mass of the lampshade.

b) Complete the sentence below.

A suspended object will come to rest with its centre of mass directly…

Q3)

In a science lesson, some children float an apple on some water.

One of the children says: “The apple is not moving. That means that there cannot be any forces acting on it.” Do you agree? Explain your answer as fully as you can.

Q4)

The image below shows the metal ball falling through the oil.

a) What is force P?

b) Between points A and B, force P is greater than force Q. Describe the motion of the metal ball between points A and B.

c) Between points B and C, force P is equal and opposite to force Q. Describe the motion of the metal ball between points B and C.

Q5)

An actor is attached to a wire so that she can hang above the stage.

Look at the figure below.

a) The actor hangs above the stage in a stationary position. What is the resultant force on the actor?

b) The actor has a mass of 70 kg. Use the following equation to calculate the weight of the actor. Give your answer to 2 significant figures.

• Gravitational field strength = 9.8 N / kg • Weight = mass × gravitational field strength

Another actor has a mass of 65 kg. This actor is attached to the wire and the motor pulls her vertically upwards. The resultant force on the actor is 25 N.

c) Write down the equation that links acceleration, mass and resultant force.

d) Calculate the acceleration of the actor. Remember the correct units (refer to Phase IV work pack).

End of Year 10 Science Work Pack Phase V

Documents

Year 10 Science Work Pack Phase V 10 Science... · 2020-06-24 · 10 Phase IV work pack Questions answered with full working out or in full sentences on paper All lessons on VLE