COMBINED SCIENCE JUNE 2026 PAPER 2 SECTION D

[00:00:02]Let us work on uh section D of June 2020 six paper.

[00:00:11]If you're new on this channel, make sure you subscribe, like and also share this video.

[00:00:17]Those who want to join our owner lessons you contact me on this number shown in your screen plus 2637862 82 464.

[00:00:33]All right without wasting much of your time let us go into today's work. First question sample to read >> state [snorts] base quantities.

[00:00:48]This is the first question. I'm sure every question.

[00:00:52]So I'm going to provide solutions for that one.

[00:00:59]All right. What are the best qualities?

[00:01:11]What are the best quantities?

[00:01:15][snorts] Uh [snorts] any two base quantities This [snorts] any two? All right, let me give you a list of them. Number one, we have time.

[00:02:16]Time is a base quantity. We have length, mass, we have temperature, [snorts] electric current, [clears throat and snorts] amount of substance, amount of substance.

[00:02:54]All right. So, mass, length, electric current, amount of substance, temperature, amount of substance, chemistry is the amount of is the amount of substance in a compound.

[00:03:21]All right, let's leave it to go and research it. According to Newton's second law of motion, force can be calculated using the formula force is equal mass time acceleration ma.

[00:03:38]Express the Newton in base units.

[00:03:44]Express the Newton in base units.

[00:03:52]What is the second law of motion says laws of all right I will break it down laws of motion you know we are in a >> [snorts] >> never know.

[00:04:36]All right. Newton's laws of motion.

[00:04:38]Number one, it said that um let's see an object at rest an object at rest an object at rest will remain at rest.

[00:05:00]An object at rest will remain at you.

[00:05:19]Unless acted.

[00:05:25]Unless acted [snorts] by any external force [clears throat] [snorts] unless acted by an external force.

[00:05:51][cough] [clears throat] Force app.

[00:06:15]It will remain at rest unless there is a force acting on it.

[00:06:25]your first law of motion or first law of movement.

[00:06:32]Uh second law you know [clears throat] the second law it says the acceleration [snorts] the acceleration of an object.

[00:06:54][clears throat and snorts] It depends on force applied.

[00:07:01][clears throat] The acceleration of an object, it depends on force applied [snorts] and its mass.

[00:07:26]>> [clears throat] [cough] >> speed.

[00:07:51]No second law.

[00:07:54]First law in not the object that is at rest, the object that is resting will continue resting unless there is an external force that act on the object force upon it.

[00:08:21]Number one law number two by the acceleration of any object it depends number one on the force applied number two its mass that's why according to the second law [cough and clears throat] but this question paper the force is equal to mass times acceleration You must highlight you must show the involvement of acceleration, the involvement of mass and the involvement of what? Force. So force of an the acceleration of an object is influenced is caused depend on the force applied and the mass of that object that is moving.

[00:09:36][snorts] Why? Because acceleration of any object it depends on what? The force applied and the mass of the object. Are you getting this? The third law it the third law it states that uh for every action there is [clears throat] an equal [snorts] >> [snorts] >> For every action there is an equal and opposite reaction.

[00:10:26][cough] Another physics It's now easy.

[00:10:50]Huh?

[00:11:07]Check out [laughter] forces.

[00:11:53]All right.

[00:12:07]I know very well.

[00:12:20]balance disease.

[00:12:22]>> All right, let's let's continue.

[00:12:25]The third says, for every action there is an equal and opposite what reaction.

[00:12:32]So what it means is that whenever an object is being pushed maybe you're pushing the object towards yourself or you're pushing the object away there is always a force that is equal to the amount of force that you are applying equal let's say I want to push uh There is ace ready to actually oppose what I'm doing.

[00:13:24]So according here whenever one object pushes another the second object pushes back.

[00:13:37]The other object is what? The second object pushes back with the same force but in the opposite direction.

[00:13:52]momentum >> in Asia.

[00:14:06]Newton's laws. It's part of Newton's laws of motion.

[00:14:23]momentum end of it's not a problem.

[00:14:46]All right, let's go. So that's those are three laws of motion.

[00:14:52]According to to Newton's second law of motion, force can be calculated using the formula.

[00:15:00]Force is called mass time what?

[00:15:02]Acceleration. Express the Newton the Newton in base units.

[00:15:33]It's 1 m per square second.

[00:15:43]>> [snorts] >> 1 m per square second [snorts] or 1 Newton. All right. Like this. One newton.

[00:16:10]>> [clears throat] >> is equal to 1 kg m per square us >> 1 kg 1 kg m s to the power minus Sit and next question.

[00:16:56][snorts] Fig 13.1 shows the readings on an instrument that was used to measure the thickness of an electric cable.

[00:17:14][snorts] Thickness of an electric cable. Name the instrument.

[00:17:28]Huh?

[00:17:29]Microme screw gauge.

[00:17:44]Next question. Determine the thickness of the electric cable.

[00:17:49]Determine the thickness of the electric cable.

[00:17:54]Determine the thickness of the electric cable.

[00:17:59]Right.

[00:18:00][snorts] This one, this scale, the first scale here is called the main scale.

[00:18:17]Then this one is called the thimble scale. [snorts] from the main let us look here this is three right and this is 3a 5 >> then four then this one is what >> four five and this one is what >> five but we don't know this space in a we don't know five the reading we're going to take five here on the main scale. So we're going to take five mm on the main scale.

[00:19:01]Right? Let us go to the thimu scale. We are going to take the readings. As you can see the readings they are increasing upwards.

[00:19:11]Right? So we have 10 1 2 3 4 5. So division 10 this line 15 1 >> five. Let us write 22 scale 22. But what we do on the thimble scale of a micrometer screw gauge we multiply it by by 0 comma 01.

[00:20:15]So we going to get 0 of the scale [snorts] 22.

[00:20:38]Right. So the reading from the main scale and the reading from the scale.

[00:20:44]What are we going to do? We are going to add the reading from the main scale plus the reading from the thing from the thimble scale. So we're going to say 5 plus what [clears throat] >> 0a 22. Then you're going to get 5 comma 2 2 mm.

[00:21:10][snorts] Right, that's it. 23 marks.

[00:21:31]Or instead of multiplying by 0 02 You divide by 10.

[00:22:09]All right. And describe how the volume of an irregular solid object can be determined.

[00:22:25]Describe how the volume of an irregular solid can be determined.

[00:22:35]All right.

[00:22:47]Go to California.

[00:22:49]Yeah, you want water resistant.

[00:22:53]You want to measure it volume. That's an irregular object. [laughter] An irregular object.

[00:23:17]Thank you.

[00:23:24]All right.

[00:23:31]This is not a measuring volume.

[00:23:41]What it means is that irregular object volume before putting the irregular object after putting the irregular object.

[00:24:02]All right. Number one, pour water into measuring cylindrig.

[00:24:15]Number one, what do you do? You pour water. Yes.

[00:24:20]>> Into a measuring what?

[00:24:22]>> Cylinder. And record the initial volume.

[00:24:26]So after pouring the water into the measuring cylinder as you can see this is our measuring cylinder. After pouring water what do we do measurement that measurement irregular object inside volume.

[00:24:48]So pour water into the measuring cylinder and record the initial what you write it down. This one number two completely immense the object in the water. In this case, you're going to put this iPhone 17 Pro Max >> completely immens but immers like completely immerse the object in the water.

[00:25:44]change. So number three, what are you going to do? Record the final volume.

[00:25:53]Record the final volume.

[00:26:07]Right. Then after that then calculate then calculate the volume of the object.

[00:26:17]Then calculate the volume of the object.

[00:26:25]Then calculate the volume of the object using the formula final minus initial.

[00:26:33]Using the formula final minus what? Initial.

[00:26:40]Using the formula final minus initial.

[00:27:03]What is the volume now of the irregular object formula?

[00:27:11]Initial volume of irregular object.

[00:27:16]Let's go to the next question. Question number 14. Define the temperature.

[00:27:22]Define the temperature is >> pressure is force per >> force acting per unit area.

[00:27:36]Force acting per what? The unit area for >> [snorts] >> pressure in general pressure is equal to force over G.

[00:28:19]Yeah.

[00:28:21]over if the is not newton there is a number that I told you you must multiply that force with this number I don't know if you still remember that Oh, move down physics.

[00:29:10][snorts] [clears throat] Next question.

[00:29:18]is for setting per unit area pressure.

[00:29:21]State the two factors that affect the pressure of a fluid.

[00:29:27]Two factors that affect the pressure of a fluid.

[00:29:34]Number one, depth of the fluid.

[00:29:45]Number [snorts] one, depth of what?

[00:29:57]>> Depth of the fluid. That's number one.

[00:29:59]Number two, density of the fluid.

[00:30:06]I'm sure you know how to calculate density.

[00:30:16]I didn't want to mention your name.

[00:30:22]Anything that is defined by saying for example we said pressure is force acting pay. [clears throat] Do you know pay it means?

[00:30:37]Yeah. I want you to check.

[00:30:50]That's why we said pressure is force over area because it's a force acting.

[00:31:02]So number one depth depth depth of the fluid pressure can pressure force let me take pressure as pressure is something that you are thinking about when you're talking about liquids like let me take the use the example of water right what you're thinking about as pressure keep it keep that one is correct I want to teach you something now do you know that these demos when they are being built they are thicker at the bottom than at the Why a is thicker at the bottom than at the top.

[00:31:53]reason at the top is to withstand pressure because pressure in liquids increase as you go down or increase with depth.

[00:32:15]pressure.

[00:32:30]We can't talk about swinging proof.

[00:32:32]Yeah, let us talk about this things.

[00:32:37]All right. So, why pressure down. Why? Because pressure it go down.

[00:33:20]greater pressure or less depth of the fluid.

[00:33:31]Let's go to the next question.

[00:33:40]>> [clears throat] >> You see now has a wider base compared to the top.

[00:33:51]Explain why this is a good design.

[00:33:56][clears throat] God is good.

[00:34:08]Huh?

[00:34:26]Water pressure increases with depth.

[00:34:31]Water pressure increases with depth.

[00:34:36]Water pressure increases with depth.

[00:34:42]So the bottom of the dam.

[00:34:48]So the bottom of the dam is wider or must be wider.

[00:35:08]So the bottom of the dam is wider because it experiences because it experiences the greatest tree pressure [snorts] because it experiences the greatest pressure or greater pressure.

[00:35:44]This is good because it makes because it makes the damn stronger.

[00:36:05]Now we have hope I'm helping you. Let us continue.

[00:36:13]How many questions do we have here?

[00:36:19]We're going to complete this topic to let's go to the question B. Fig 14.1 shows a type of a single pump during its down.

[00:36:41]What happens to valve A?

[00:36:44]It opens apve the upper valve thenve waterveve let's go the question I pump the type of Um, is it not G? It's not reasonable. Lift B.

[00:37:37]God adise you.

[00:37:41]lift gym lift.

[00:37:50]Item two, describe the events occurring during the upstroke of the of the pump.

[00:38:05]Moving up is moving.

[00:38:11]Thenve to open valve Ah, you know, close.

[00:38:32]Describe what needs to be done before the pump can be used.

[00:38:41]What are the drawbacks or disadvantages or limitations of a lift?

[00:38:50]It's a limitation.

[00:38:54]Need to be primed first.

[00:39:00]Need to be primed first.

[00:39:04]>> [snorts] >> need to be primed first. All right, teachers continue.

[00:39:14]We're going to do the last question which is question number 15 tomorrow.