3.5 Pressure on solids

Pressure on Solids

Pages 166-167

Learning objectives;

• Calculate pressure.

• Apply ideas of pressure to different situations.

Lesson explainer Videos;

1. Pressure in gasses; Pressure in Gases | Matter | Physics | FuseSchool

2. Pressure in liquids; Pressure in liquids | Matter | Physics | FuseSchool

3. Pressure in Solids;  GCSE Physics - What is Pressure?  #48.

   Watch the pressure on solids video and continue with the lesson here

Lesson objectives;

Use pages 166-167 to complete this lesson.

At the end of this lesson, you should be able to;

1. Calculate pressure

2. Apply ideas of pressure to different situations

Multiple Choice

Page 166

When you stand on a surface, you exert a ____ on it because of your ____.

• Force, Pressure

• Force, Mass

• Pressure, weight

• Force, weight

Multiple Choice

Page 166

When you are standing on the floor, your weight is spread out over the ___ of your foot

• weight

• pressure

• area

• mass

Multiple Choice

A metric ton excavator in this picture is able to operate on the muddy ground without sinking. How is this possible?

• It has strong tyres

• Humans are not made of metal

• It has a large surface area

• It has a large mass

Multiple Choice

If an object's surface area is smaller does it create more or less pressure?

• More

• Less

• The same

Multiple Choice

Why won't you sink in mud if you wear boots?

• Because the surface area is larger creating less pressure.

• Has air in it to keep you floating.

• Because the mud won't want you.

Multiple Choice

What is pressure?

• The amount of force exerted on a surface area

• The surface area of an object

• The weight of an object

Multiple Choice

True or false;

Pressure acts in a direction that is 90 degrees to the surface.

• TRUE

• FALSE

Multiple Choice

State the direction at which pressure acts?

• 420^o

• 180^o

• 90^o

Multiple Choice

Page 166

A direction of 90 degrees is '______' to the surface.

• normal

• abnormal

• high

• adjacent

Multiple Choice

The force which acts perpendicular to the table, and which supports the computer resting on the table is called ........... force

• balanced

• unbalanced

• Normal

• Tension

Multiple Choice

Name the missing force....

• weight force

• normal force

• frictional force

• tension force

Multiple Choice

The force that keeps objects on top of surfaces instead of letting them sink into the surface is known as:

• normal

• abnormal

• static

• inertia

Multiple Choice

Name the missing force...

• weight force

• normal force

• applied force

• frictional force

Multiple Choice

The Coffee cup in the picture is resting on a table. What force(s) are missing from the free body diagram?

• No forces are missing

• The normal force from the table pushing the cup up.

• The normal force form the table pushing the cup down.

• The friction force from the table pushing the cup left and right.

Multiple Choice

Page 166;

How do you calculate pressure?

• Preesure = ForceXArea

• Pressure = Force/Area

• Pressure = Area/Force

• Pressure = Weight

Multiple Choice

Page 166

What are the SI units of pressure?

• Newtons

• Metres

• Newtons/Metres

• newtons per metre squared

Multiple Choice

Google this;

Which of the following is an alternative unit for pressure named after a scientist and mathematician?

• Pascals

• Kelvins

• Watts

• Faradays

Multiple Choice

Page 167

Why do you wear studs on grass?

• Because the studs create more pressure allowing it to grip into the grass.

• Stylish

• Creates friction

Multiple Choice

How do you Calculate Pressure

• Force(N)/Area(m²)

• Force(kg)/Area(mi²)

• Area(m²)/Force(N)

Multiple Select

If the pressure exerted by your finger is 1 Pascal, what does this mean? (Select two answers)

• Pressure = 1 newton per square meter

• One newton of force is exerted on one square meter of a surface

• One newton of force is exerted on on square centimeter of a surface

• Pressure = 1 newton per meter

Multiple Choice

Recall; Unit conversions

1 m = ____ cm

• 1

• 10

• 100

• 1000

Multiple Choice

Recall; Unit conversions

1 square meter = ____ square centimeters

{ 1 m² = _____ cm²}

• 100

• 10,000

• 100,000

• 0.0001

Multiple Choice

Think! ~ work your brain.

1 N/m² = ______ N/cm²

• 10

• 0.1

• 10000

• 0.0001

Multiple Select

Which of the following are correct units of pressure? (Select 3 answers)

• N/m²

• N/cm²

• Pascals

• N/m

Multiple Choice

What is the standard unit of pressure used in science?

• N/m²

• N/cm²

Multiple Select

A person weighs 700N and their feet have a surface area of 0.1m². How much pressure is exerted? (Select two answers)

• 7000N/m²

• 70N/cm²

• 100N/m²

Multiple Choice

What does N/m² mean?

• Newtons per squared metre

• Kilograms per squared mile

• Squared metres per newton

Multiple Choice

How do you turn Ncm² to Nm²?

• Divide by 100

• Divide by 10

• Times by 100

Multiple Choice

What pressure does a 4000N horse exert on the ground if each foot is 10cm²?

• 40 N/cm²

• 100 N/cm²

• 400 N/cm²

• 10 N/cm²

Multiple Choice

If the horse reared up on 2 legs what effect would it have on the pressure?

• it will exert half the pressure it did before

• it will exert the same pressure it did before

• it will exert twice the pressure it did before

• it will exert four times the pressure it did before

Multiple Choice

Which of these animals would probably cause the greatest pressure on the ground?

• A fat cow with big feet

• A fat cow with small feet

•  A calf with big feet

• A calf with small feet

Multiple Choice

A cardboard box weighs 30N. If we added weight to the box, what would happen to the pressure?

• increase

• decrease

• stay the same

Multiple Choice

Which situation produces more force on the floor?

• standing on one foot

• standing on two feet

• standing on four feet

• all produce the same force

Multiple Choice

Which situation produces more pressure on the floor?

• standing on one foot

• standing on two feet

• standing on four feet

• all produce the same pressure

Multiple Choice

Look at the pressure triangle. How do we calculate the area?

• f ÷ a

• f x p

• p x f

• f ÷ p

Multiple Choice

Look at the pressure triangle. How do we calculate the force?

• f ÷ a

• f x p

• p x a

• f ÷ p

Multiple Choice

Pressure is measured in what units

• Newtons

• m/s

• Pascals

• Moles

Multiple Choice

Pressure is equal to force divided by what

• area

• mass

• time

• distance

Multiple Choice

The pressure resulting from a force of 50 N exerted over an area of 5 m² is

• 10 N

• 0.1 N

• 10 N/m2

• 0.1 Pa

Multiple Choice

Which of the statements is true?

• The bottom of the boot exerts more pressure than the shoe as a result of an increase in surface area.

• The bottom of the shoe exerts more pressure than the boot as a result of an decrease in surface area.

• The bottom of the shoe exerts the same pressure as the bottom of the boot.

Multiple Choice

Army tank tracks are useful for travelling through the mud because..

• they decrease the force the vehicle exerts on the ground

• they increase the force the vehicle exerts on the ground

• they decrease the pressure the vehicle exerts on the ground

• they increase the pressure the vehicle exerts on the ground

Multiple Choice

A person wearing steel toe capped boots and a person wearing stilleto heels stand on a wooden floor. They both have the same weight. Which person exerts a greater pressure on the floor?

• The person wearing the boots because the boots have a larger surface area in contact with the floor

• The person with the stiletto heels because they have a larger surface area in contact with the floor

• The person wearing the boots because the boots have a smaller surface area in contact with the floor 

• The person with the stiletto heels because they have a smaller surface area in contact with the floor

Multiple Choice

Which sentence is the MOST RIGHT fit for this image?

• Flat shoes are better than heels.

• Pressure distribution is less for flat shoes.

• In muddy area, it's not a good idea to wear heels.

• Less the area, less is the pressure. So heels create less pressure.

Multiple Choice

Why won't you sink in mud if you wear boots?

• Because the surface area is larger creating less pressure.

• Has air in it to keep you floating.

• Because the mud won't want you.

Multiple Choice

Watch the tyres of tractor rolling. Rear tyres are broader because

• It looks good.

• Broader tyres lessen the muscular Force required.

• Broader tyres lessen the pressure on ground.

• Broader tyres lessen the friction on ground.

Multiple Choice

A force of 240 N is applied to an area of 6.0m². how much pressure is being applied to the surfaced?

• 14,400 Pa

• 40 Pa

• 240 Pa

• 6.0 m²

Multiple Choice

A force creates a pressure of 12 Pa over an area of 6.0 m². What is the magnitude of this force?

• 72 N

• 12 N

• 6.0 N

• 2 N

Multiple Select

What were today's lesson objectives?

• Calculate pressure

• apply ideas of pressure to different situations

• play typing tutor

• waste school fees

Poll

EXIT TICKET

Do you know how to calculate pressure?

• Nope, I don't get it

• A little bit

• YES, but the units confuse me

• YES; Pressure = Force/Area, Units are Pascals, N/m² or N/cm²

Multiple Select

EXIT TICKET;

What are some situations in which ideas of pressure apply?

• Heavy excavators having big tyres

• Stilettos are not good for grass, sports, or hiking

• Small surface area = Large pressure

• Large surface area = small pressure

• Pressure = area/force