1. 1 thing you learned today

2. 1 thing you would like to learn more about

3. 1 thing you wonder about today's learning

1. Please share one lesson/topic that you feel engages you most. Why?

2. Please share one thing that you think you like to do more for the learning of physics.

3. Any question you have for me?

Let's respect each other in this space by giving words of encouragement when making comments and ensuring any picture/photo we post does not undermine any one's dignity.

I look forward to hearing your voices in this space. Please date your post (see Kenisha's post :))

1 thing I would like to learn more about: applying it in practical situations

1 thing I wonder about today’s learning: nil so far

The binder clip has a larger mass and hence the centre of gravity of this toy is at the binder clip, and directly below the pivot.

1. As this toy is tilted slightly, the centre of gravity is raised and weight provides an anticlockwise moment that restored the object towards to its original position.

2. Due to inertia, the toy oscillates towards the right and the weight provides a clockwise moment that restored the object towards to its original position.

3. The oscillation of the toy continues but becomes smaller due to resistive force and eventually the toy returns to its original position where the centre of gravity is directly below the pivot, perpendicular distance = 0, resultant moment = 0.

P=F/A, the surface area is very small, so the pressure is higher, therefore the ice skaters can move on the ice faster.

ice skating have sharp blades as there is a smaller amount of skat blade on the ice and there will be more pressure on the ice and the person can skate more easily and faster,

Melts the ice forms a layer of water to glide through the ice

the small blade concentrates the skaters weight on a small area which increases pressure on the ice and allows for better grip to move faster

(Melt ice->lubricate skates)

The sharp blades have a small contact area allowing there to be greater pressure exerted on the ice by the ice skates so ice skaters can move faster

The reasoning is that due to the high pressure the skates put on the ice, it will melt at temperaturs below 273K and thus provide a thin film of liquid on which we can skate. It was then mentioned as fun fact that you could ice-skate on a planet with lakes of frozen dioxide because that gas has the p(T)-curve the other way round.

P=F/A

Force exerted is the same. If the blade is sharp, the surface area decreases, therefore the pressure increases. The blade cuts and melts the ice more when pressure increases which helps the skater skate more easily.

20cm=0.02kg

80N/0.02kg=4000N/kg

20cm=0.2m

0.1m x 0.2m = 0.02m2

8 x 10= 80N

80 / 0.02 = 4000pa

20cm = 0.2m

0.1 x 0.2 = 0.02m^2

8.0 x 10 = 80

80 x 0.02 = 4000Pa

ans: (c)

To get Minimum P u have to divide by maximum Area which is 0.2x0.1=0.02 which is m^2 in SI unit then take the force which is 8x10=80N divided by the area 0.02m^2 answer is 4000Pa

Area= 10 x 2 =20cm2

20cm2= 0.02m2

Pressure= 80/0.02 = 4000Pa

Ans: C

= 0.02m^2

Force = 8kg x 10N/kg

= 80N

Pressure = 80N / 0.02m^2

= 4000Pa

= 4000pa

w=8.0x10

=80N

largest area= 20cm x 10cm

= 0.2m x 0.1m

= 0.02m^2

P=F/A

=80/0.02

= 4000Pa

ans (c)

force: 8 x10=80N

Area= (10x2)/1000=0.02m^2

pressure= 80/0.02=4000Pa

Area= 10 x 20= 200cm^2= 0.02m^2

P= F/A= 80/0.02 = 4000Pa (c)

P=[(10x8)x1000]/2x10=4000 Pa

A = 10 x 2 = 20cm^2

= 0.02m^2

F = 8.0 kg x 10 N/kg

= 80 N

P = 80 N / 0.002 m^2

= 4000 Pa

P = F/A

A (greatest area) = (20 / 100)(10/100)

= 0.02m^2

P= (8.0 x 10) / 0.02

= 4000 Pa

10/100=0.1m 2/100=0.2m

0.1 x 0.2=0.02msquared

Pa=80/0.02=4000pa

10cm=0.10m

2cm=0.02m

Area of surface area=0.10x0.02

=0.002m^2

Pressure=10/0.002

=5000Pa (X)

CORRECTIONS

Force

=8kgx10N/kg

80N

Area

=0.2x0.1

=0.02m^2

Pressure

=80N/0.02m^2

=4000Pa

force = 8.0 x 10 = 80N

area = 0.2 x 0.1 = 0.02m^2

pressure = 80N/0.02m^2 = 4000Pa

Weight=8.0kg x 10N/kg =80N

Surface area=0.1mx0.2m=0.02m2

Pressure=80/0.02=4000Pa

•If a pressure is applied to an enclosed liquid, the pressure is transmitted to all other parts of the liquid undiminished – Pascal’s Principle or Pascal’s Law.

• 1 concept I know well :)

• 1 concept I need to revise

• 1 specific action I will take to revise this topic 💪

Updates! Here's the questions and explanations

Pressure in day-to-day life

• 1 concept I need to revise

How to measure pressure

• 1 specific action I will take to revise this topic 💪

Memorise the formulae and familiarise myself to manometers

1 concept I need to revise: barometer

1 specific action I will take to revise this topic: reread notes and ws, make sure i know my mistake and understand. clarify if there’s any doubts

2 Need to revise measuring pressure in liquid

3 will do more practice

2 pressure of gases

3 keep practising and practising

1 concept i need to revise is barometer and manometer

1 specific action i can take is to do the TYS and practice the skills.

I need to revise on finding the pressure and density from the manometer and barometer diagram

Spend some time at home revising

I understand how to find pressure using the 2 formulas P = F/A and P = hρg

• 1 concept I need to revise

Barometer and Manometer

• 1 specific action I will take to revise this topic

I will look through my notes and attempt more practices

-finding the pressure in water

1 concept I need to revise

-manomoters and barometers

1 specific action I will take to revise this topic 💪

-revise the notes and try different questions

Pressure: Force/Area

1 concept I need to revise:

Measuring pressure in a liquid column

1 specific action I will take to revise this topic:

Do pressure questions from the physics 10 year series book

1 thing I need to work on is the part on manometers and barometers + p=hpg.

I will work on it by practising the 10 year series until I grasp the concept better:)

2) hydraulic systems

3) practise doing questions

1 concept I don’t know is when to use what formula

I will practice more practices on pressure

I can have a better understanding of how to use the formulas with other formulas for moments, forces, etc.

I will try to revise my worksheets.

Ms Ong

• use this same title

• feedback by SLS/ what are the points you missed out for both parts.

b) You mentioned that the weight of the metal sheet produces a moment about pivot A causing the sheet to rotate clockwise, which is one of the points. However, to fully meet the criteria, you need to include all four points: the overshooting due to inertia, the anticlockwise moment, and the oscillation until the center of gravity is directly below pivot A.

I think i kinda get where i’m wrong cause i never write about the overshoot due to inertia and the anticlockwise motion i only say “Due to inertia” so i also think i’m wrong

I left out the resultant moment is 0 due to weight

b)Your response includes some of the key points, such as the weight providing a clockwise moment and the oscillation of the sheet. However, it lacks a clear mention of the sheet overshooting the position due to inertia and the restoring moment in the opposite direction. To improve, ensure that all critical points are covered and described accurately.

You have provided a clear and scientifically accurate explanation of the clockwise moment caused by the weight of the sheet. However, you only covered one of the four key points. To improve, make sure to include all relevant points such as the overshoot due to inertia, the anticlockwise moment, and the eventual oscillation until the centre of gravity is directly below pivot A.

Q1) You correctly identified the perpendicular distance and used the correct formula to calculate the moment. However, you missed converting the mass from grams to kilograms, which is crucial for accurate calculations. Make sure to check your units next time.

Q2)Your response included two of the four key points: the restoring moment causing clockwise rotation and the oscillation due to inertia. However, it missed the overshooting of the center of gravity and the subsequent anticlockwise restoring moment. Additionally, the terminology used was not entirely accurate. Aim to cover all key points and use precise terms in your explanations.

Q2- You correctly identified that the weight of the metal sheet creates a clockwise moment about the pivot. However, to fully meet the criteria, you needed to mention the sheet's rotation, overshooting due to inertia, the anticlockwise moment, and the eventual stabilization. Your response was clear and scientifically accurate but lacked the complete explanation required.

b. You have provided two of the four key points: the final position of the sheet and the initial clockwise moment. However, your response lacks the details about the sheet overshooting due to inertia and the subsequent anticlockwise moment. Make sure to include all these points for a complete answer.

2) You mentioned the center of gravity and moments, but your response only partially addresses the required points. To improve, you should include all four key points: the clockwise moment causing rotation, the overshooting due to inertia, the anticlockwise moment, and the oscillation until the center of gravity is directly below the pivot. Ensure your answer is scientifically accurate, clear, and coherent.

You have correctly identified the perpendicular distance and converted the mass, but you did not show the detailed steps for the conversion. Ensure to include all steps in your working for full clarity.

2) Your response mentions that the sheet will oscillate and come to rest, but it lacks the necessary scientific details and clarity. To improve, you should include all four key points: the weight of the metal sheet providing a clockwise moment about pivot A, the sheet overshooting the position due to inertia, the weight providing an anticlockwise moment, and the sheet oscillating until the center of gravity is directly below pivot A.

W=mg

W= 0.25x10= 2.5N

M= dxF

M= 0.30x2.5 =0.75Nm (Ans)

You have demonstrated a clear understanding of the problem by correctly identifying the perpendicular distance and converting the mass. Your final answer is correct and includes the appropriate units of Nm. Great job!

Q2) The sheet is in equilibrium. When the center of gravity , point G is directly below the pivot point, A, the weight does not provide any moment about the pivot to cause it to move. This is because M=dxF and the perpendicular distance between the pivot and the center of gravity is zero, 

You mentioned the equilibrium condition accurately, but you did not cover the process of how the sheet reaches that state. To fully answer the question, you need to explain the moments and oscillations that occur when the sheet is released.

1b) Your response partially addresses the final state of the object but misses key points about the process leading to this state. To improve, you should mention the initial clockwise moment caused by the weight of the metal sheet, the overshooting due to inertia, and the subsequent anticlockwise moment. This would make your explanation more scientifically accurate and coherent.

Suggested answer: 4. Therefore, the sheet will oscillate about A until eventually the centre of gravity is directly below pivot A, the perpendicular distance between line of action of weight and pivot A is zero, there is no resultant moment due to the weight. 

This AI sucks. I did include everything correctly except for converting grams to kilograms >:(

2. Your response shows a good understanding of the concept of oscillatory motion and inertia. However, to fully meet the criteria, you need to mention the direction of the moments (clockwise and anticlockwise) and the final position where the center of gravity is directly below pivot A. Keep up the good work and try to include these details in your future responses.

I left out the words clockwise and anti clockwise. Instead, i used “left” and ”right”. Ill remember next time

a: You correctly identified the perpendicular distance and the final answer with the correct units. However, you missed the conversion of mass from grams to kilograms. Ensure to include all necessary conversion steps in your calculations to avoid errors.

b: You have provided two of the four key points required: the clockwise moment causing rotation and the overshooting due to inertia. Your response is scientifically accurate and coherent, but it lacks the details about the restoring moment being about pivot A and the final position of the center of gravity being directly below pivot A. Focus on these missing details to improve your explanation.

-I can add in the part about the sheet overshooting its position and the perpendicular distance being zero at the end.

SLS feedback:

Your response includes two of the four key points: the clockwise moment due to the weight and the oscillation about the equilibrium position. Your explanation is scientifically accurate, clear, and coherent. To improve, you should include the point about the sheet overshooting the position where the center of gravity is directly below the pivot due to inertia, and the final position being the center of gravity directly below the pivot.

Your response includes some relevant concepts such as the clockwise moment and inertia. However, it only partially addresses the key points required. It does not mention the overshooting of the position where the center of gravity is directly below pivot A, the anticlockwise restoring moment, and the eventual oscillation until the center of gravity is directly below pivot A. To improve, ensure to include these aspects in your explanation.

This feedback is quite accurate as my explanation of how the inertia of the sheet affected its movement was inaccurate.

Q2) You have provided a scientifically accurate and clear explanation of one of the key points, which is a good start. However, to fully meet the criteria, you need to include at least one more key point from the answer scheme. Make sure to mention the overshooting due to inertia and the subsequent anticlockwise moment, as well as the oscillation until the center of gravity is directly below pivot A.

Calculate the power developed in climbing a flight of stairs.

Time: 10 min

Post your solution clearly

• Title: Names of group members

• Measurement taken

• formula used and appropriate units

20 minutes

• Formation of Groups: Divide students into groups of 4-5.

• Task Assignment: Each group will be assigned one type of energy resource. Please research and discuss the assigned resource in terms of efficiency, cost, reliability, and environmental impact.

• Proposal Development: Each group will propose the best energy solution for Singapore based on their discussion and provide reasons to support their choice (Use relevant reports/ articles).

• Presentation Preparation: Groups will prepare a short presentation (1 minute) to share their proposal with the class. Format: Slides, Infographic etc

Suggested References:

1. https://www.edb.gov.sg/en/business-insights/insights/what-could-singapores-energy-mix-look-like-in-2035.html

2. https://www.greenplan.gov.sg/

3. https://www.ema.gov.sg/

4. Channelnewsasia

Time taken - 6.4s

Parallel Distance- 3.81m

Work done= force x parallel distance

=430 x 3.81

= 1640J

Power = work done/ time

= 1640/6.4

=256W(3sf)

Time taken=5.61 seconds

Distance moved in direction of force=3.7m

Weight/Force=480N

Work done=Fxd

=480x3.7

=1776 J

Power = Work done / time

= 1776 / 5.61

=317W (3sf)

W= mg = 10 x 53.5= 535

Distance (height) = 13.5cm = 0.135m

Time taken = 7.6 seconds

(0.135 x 12 x 535 )/7.6 = 114W (3sf)

E=GPE gain

GPE= mgh

Vertical height= 12.3×12/100=1.476

m=39

t= 8.96

GPE/t= 1.476(10)(39)÷8.69= 66.24W

Distance used was the height of stairs= (13.5/100) x 12

Power= workddone divided by time in seconds

= 745.2/7.16 =104watts

= [10N/kg x 48kg x (0.127m x 12)] / 6.35s

= 115W

force = 52 x 10

= 520

dist = 3.5m

time = 6.4s

power = work done/time

(520 x 3.5)/6.4 = 284W (3sf)

height=(12.6/100) x 12

=1.512m

time taken=6.26s

work done= (10)(40) x 1.512

=604.8 J

power= work done/time

=604.8/6.26

=96.6 W (3sf)

=12.7cm x 12

=152.4cm

=1.524m

Energy converted=mgh

=48.7x10x1.524

=742.188J

Time taken=3.9s

Power=E/t

=742.188/3.9

=190.304

=190W (2sf)

Average time taken to climb up stairs = 6.75s

Average weight of our members = 47.1

Work done = (47.1kg x 10N/kg)/1.635m

= 770.085J

Power developed = 770.085J/6.75s

= 114.08

= 114W (3 s.f.)

What is Brownian Motion? What do you observe? What do you deduce?

• Relate the rise in temperature of a body to the increase in average kinetic energy of all the particles in the body.

Task:

Explore the simulation and explore how the temperature of the body is related to the average kinetic energy of all the particles in the body. Post your observation under your name.

•Explain the pressure of a gas (relate to force) in terms of the motion of its particles.

Task:

Use light particles. Fixed Volume. Once the pressure stablises, start to heat the gas. Observe how the motion of the particles (collision with the walls of the container) is affected and how the pressure changes.

Post your observation under your name. Remember to explain in terms of forces.

When the particles are heated, energy is transferred to the kinetic stores of the particles, causing them to move faster. The particles collide into the walls more often, hence more force is being exerted on the walls. As pressure = force/area, the increase in total force leads to an increase in gas pressure.

• When the gas is heated, the particles move more quickly, the rate and strength of collision with the surrounding walls increases. This is because of the gain in kinetic energy within the particles, causing them to move at a faster rate and hence, exert more force onto the walls as the speed increases, thus increasing its pressure.

Temperature

• as the liquid is heated, the total kinetic energy increases as the particles moved faster. therefore the faster the particles move, the higher the temperature.

2) as temperature increases, pressure particles exert on the inner walls of glass container increases

As the gas is heated, the particles collide with and exert a force on the walls of the container at a higher rate. The average force exerted by the particles per unit area increases, leading to a higher pressure. This is because P=F/A and a larger force would result in a higher pressure for the same area, which are the inner walls of the container.

As the temperature of the body increases, average kinetic energy of the particles in the body increases.

-as the frequency of the collisions of the particles with the walls increased, the pressure of the gas increased. The pressure is the average force exerted by the gas per unit area. When the particles collide with the walls of the container, they exert a force on the walls. Hence, when the particles collide more frequently with the walls of the container, the force exerted by the particles increases, and the pressure of the gas rises.

When the particles are heated up, they move at a faster speed, increasing the rate of the particles colliding with the walls of the container. The pressure also increases.