MATERI KINEMATIK kelas 11 bag 4 GERAK LURUS BERATURAN GLB K Merdeka

Summary

This lesson explains the concepts of straight motion, focusing on two types: uniform linear motion (GLB) and uniformly accelerated motion (GLBB). It differentiates between horizontal (x-axis) and vertical (y-axis) motion, using examples such as walking and throwing an object. The lesson introduces key formulas for calculating distance, speed, and time, emphasizing the importance of units and conversions. Through practical examples, students learn how to solve motion problems and understand how graphs represent uniform motion. A practice section encourages learners to apply these concepts for deeper understanding.

Takeaways

• 📏 Linear motion refers to the movement of an object along a straight path.
• 🚗 There are two types of linear motion: Uniform Linear Motion (GLB) and Uniformly Accelerated Linear Motion (GLBB).
• ⬅️ GLB refers to motion where the speed is constant, and the acceleration is zero.
• 🎯 In GLB, the velocity remains the same over time, and the acceleration is zero since there is no change in speed.
• 📊 The graph of velocity (V) versus time (T) in GLB is a straight line, showing constant speed.
• 📐 The equation for GLB is X = V * T, where X is distance, V is velocity, and T is time.
• 📏 GLBB, on the other hand, involves changing velocity, which can be horizontal (x-axis) or vertical (y-axis).
• 🕒 In GLBB, velocity can either increase or decrease over time, resulting in a curved graph for position (X) vs time (T).
• ✏️ Practical examples in the video include solving for distance and speed, using the formula X = V * T and converting units from km/h to m/s.
• 💡 The lesson encourages students to practice solving problems related to uniform motion by changing units and applying the correct formulas.

Q & A

What is the definition of linear motion (gerak lurus)?

Linear motion is the movement of an object along a straight path. It means the object's trajectory is a straight line.

What are the two types of linear motion?

The two types of linear motion are Uniform Linear Motion (Gerak Lurus Beraturan - GLB) and Accelerated Linear Motion (Gerak Lurus Berubah Beraturan - GLBB).

What is uniform linear motion (GLB) and its characteristics?

Uniform linear motion (GLB) occurs when an object moves with a constant speed. The key characteristics of GLB are constant velocity and zero acceleration.

What is accelerated linear motion (GLBB), and what are its types?

Accelerated linear motion (GLBB) involves a change in velocity over time, meaning the object is either speeding up or slowing down. There are two types: horizontal GLBB (movement along the x-axis) and vertical GLBB (movement along the y-axis).

How does the velocity-time (v-t) graph look in GLB?

In uniform linear motion (GLB), the velocity-time graph is a straight, horizontal line because the velocity remains constant.

How does the position-time (x-t) graph behave in GLB?

The position-time (x-t) graph in GLB has a straight slanted line, showing that the object covers equal distances over equal intervals of time.

What is the formula for distance in uniform linear motion?

The formula for distance (x) in uniform linear motion is x = v * t, where 'v' is velocity and 't' is the time taken.

How do you convert velocity from km/h to m/s?

To convert velocity from km/h to m/s, multiply the value by 1000 to convert kilometers to meters, then divide by 3600 to convert hours to seconds. For example, 54 km/h is equal to 15 m/s.

What is the acceleration in uniform linear motion (GLB)?

The acceleration in uniform linear motion (GLB) is zero because the velocity is constant and does not change over time.

How would you calculate distance if a car is moving at 15 m/s for 300 seconds?

Using the formula x = v * t, where v = 15 m/s and t = 300 seconds, the distance traveled is 4500 meters.

Outlines

00:00

📏 Introduction to Linear Motion

The speaker begins by explaining the concept of linear motion, where the movement of an object follows a straight path. Two types of linear motion are introduced: uniform linear motion (Gerak Lurus Beraturan, GLB) and uniformly accelerated linear motion (Gerak Lurus Berubah Beraturan, GLBB). GLBB is further divided into horizontal (along the x-axis) and vertical (along the y-axis) motion. An example of horizontal motion is walking, while vertical motion involves throwing objects up or down. The focus is then shifted to GLB, where speed remains constant, and acceleration is zero. Various characteristics of GLB are explained, such as the consistent velocity and how the v-t and x-t graphs behave.

05:01

📝 Calculating Distance in Uniform Motion

This paragraph delves into the formula used to calculate distance in uniform motion: X = V * T or V = X/T, where X is distance, V is velocity, and T is time. The speaker reminds the audience of the simplified form of this formula from elementary school (JKW = jarak, kecepatan, waktu), but emphasizes the proper use of symbols in high school physics. The example provided involves converting units, such as velocity from km/h to m/s and time from minutes to seconds, then applying the formula to find the distance traveled. The example shows how a car moving at 15 m/s for 300 seconds covers 4500 meters.

🤔 Problem-Solving Example: Speed and Time

The speaker introduces a problem-solving exercise for the students, focusing on calculating speed when given distance and time. In this exercise, time is given in minutes, and the students must convert it to seconds before solving the problem. The speaker encourages students to recall how to convert units from earlier lessons and apply these techniques to find the solution. The paragraph ends by prompting students to continue learning through the next instructional video.

Keywords

💡Gerak Lurus

Gerak lurus refers to motion in a straight line. In the video, it is described as the movement of an object where the path or trajectory is a straight line. This concept is fundamental in understanding different types of linear motion, such as uniform motion and uniformly accelerated motion.

💡Gerak Lurus Beraturan (GLB)

Gerak Lurus Beraturan (GLB) is uniform linear motion, where an object moves at a constant speed along a straight path. In the video, it is explained as having zero acceleration, meaning the velocity remains constant. This type of motion is depicted in the example where the object's velocity stays at 10 m/s with no change over time.

💡Gerak Lurus Berubah Beraturan (GLBB)

Gerak Lurus Berubah Beraturan (GLBB) refers to uniformly accelerated linear motion, where an object experiences constant acceleration. This is contrasted with GLB in the video, and the GLBB has two forms: horizontal and vertical, which involve motion in the x-axis and y-axis, respectively, such as throwing an object up or down.

💡Kecepatan (Velocity)

Kecepatan, or velocity, refers to the speed of an object in a specific direction. In the video, velocity is crucial in calculating motion for both GLB and GLBB. For GLB, velocity remains constant, while for GLBB, it changes due to acceleration. The formula for velocity is often V = s/t, where 's' represents distance and 't' time.

💡Percepatan (Acceleration)

Percepatan, or acceleration, refers to the rate of change of velocity over time. In the video, acceleration is zero in GLB since the velocity is constant, but in GLBB, acceleration is present and causes changes in the object's speed over time. Acceleration is the core difference between GLB and GLBB.

💡Horizontal dan Vertikal

Horizontal and vertical refer to the directions of motion in GLBB. Horizontal motion occurs along the x-axis (such as walking), while vertical motion happens along the y-axis (such as throwing an object up or down). The video emphasizes understanding the distinctions between these two types of directional movement when studying linear motion.

💡Sumbu X dan Sumbu Y

Sumbu X (x-axis) and Sumbu Y (y-axis) are the horizontal and vertical axes in a graph that represents motion. The video uses these axes to explain how different types of linear motion are plotted, with horizontal motion on the x-axis and vertical motion on the y-axis. This is essential for analyzing motion in two dimensions.

💡Grafik V terhadap T (Velocity-Time Graph)

A velocity-time graph (V against T) shows how an object's velocity changes over time. In the video, the graph is used to explain the behavior of objects in GLB, where the graph is a straight line because velocity remains constant. The graph helps visually represent the lack of acceleration in uniform motion.

💡Rumus GLB

The formula for GLB is S = V * T or V = S/T, where S represents distance, V velocity, and T time. This formula is used to calculate distance traveled or velocity during uniform motion. The video provides examples of how to apply this formula in different problems, emphasizing the importance of unit conversion for correct calculations.

💡Unit Conversion

Unit conversion is the process of converting measurements from one unit to another, such as from kilometers per hour (km/h) to meters per second (m/s). The video shows how to convert units when solving problems, such as converting 54 km/h to 15 m/s to calculate the distance traveled by a car.

Highlights

Introduction to straight-line motion (gerak lurus)

Definition of straight-line motion as a movement along a straight path

Explanation of two types of straight-line motion: uniform (GLB) and non-uniform (GLBB)

GLBB motion can be horizontal or vertical

Horizontal motion is discussed along the x-axis

Vertical motion is discussed along the y-axis

Example of horizontal motion: walking

Example of vertical motion: throwing an object up or an object falling down

Discussion on uniform straight-line motion (GLB)

Illustration of GLB with constant speed from 0 to 10, 20 to 30

Characteristics of GLB: constant speed and zero acceleration

Explanation of how to calculate acceleration: final speed minus initial speed over time

Description of the timer results for GLB: equal-sized points indicating constant distance

Graph of velocity (V) versus time (t) for GLB is a straight line

Formula for GLB: S = V * T or V = s/t

Explanation of the symbols used: X for distance, V for velocity, and t for time

Mnemonic for remembering the formula: JKW (jarak = kecepatan dikali dengan waktu)

Example problem 1: A car moving at a constant speed of 54 km/h

Conversion of speed units from km/h to m/s

Calculation of distance traveled in a given time

Example problem 2: An object moving with uniform straight-line motion (GLB)

Explanation that the speed in GLB is constant and acceleration is zero

Encouragement for students to practice with the provided exercises

Invitation to continue with the next learning video

Transcripts

Nah sekarang kita lanjutkan bagian yang

c yaitu gerak lurus nah gerak lurus itu

adalah maksudnya gerak lurus adalah

Gerak suatu benda yang lintasannya

berupa garis lurus berarti ini dia

lintasannya lurus ya kemudian gerak

lurus itu nanti kita pelajari ada dua

jenis yang pertama gerak lurus beraturan

yaitu kepanjangannya kependekannya GLB

Ya gerak lurus beraturan dan gerak lurus

berubah beraturan yaitu GLBB nah GLBB

ini juga ada dua nanti yaitu horizontal

dan vertikal horizontal itu kita

bahasnya adalah di sumbu x ya vertikal

itu adalah di sumbu y Jadi kalau di

sumbu x ini Contohnya kayak kita

berjalan gitu ya kalau vertikal itu

Contohnya kayak kita melempar benda ke

atas atau benda jatuh ke bawah oke nah

pertama kita bahas dulu gerak lurus

beraturan GLB ya Nah jadi di sini

contohnya ilustrasi dari GL itu ini

misalnya dari 0 sampai ke-10 jaraknya ya

dari 10 20 20 ke 30 itu dia kecepatannya

tetap ya nah nih lihat nih ini 10 10

jadi artinya di sini

kecepatannya tetap dan percepatannya 0

karena kecepatannya tetap berarti kan

kalau kita kurangkan awal dengan akhir

kan 0 jadinya percepatannya 0 sedangkan

v-nya tetap itu ciri-ciri GLB ya

Kemudian yang kedua kalau hasil dari

tikar timernya itu titik-titiknya adalah

sama sama besar ya jaraknya kemudian

yang ketiga kalau grafik V terhadap t

dia akan lurus saja Jadi kenapa lurus

karena dia itu v-nya tidak berubah

meskipun kayaknya berubah misalnya di

sini C1 ini T2 jadi berapapun waktunya

dari satu detik dua detik tiga detik

tetap v nya segitu aja kan tetap 10

Nggak berubah ya Nah kemudian sedangkan

grafik grafik X terhadap TX itu kan

jarak ya kita tahu jarak itu dan t jadi

dia mengalami apa

miringnya ada kemiringan nah sehingga

nanti bisa kita cari rumus dari GLB itu

adalah S = V * T atau V = s/t dimana Oh

ya Ini seharusnya bukan es ya Ini

seharusnya x oke

ini x ini x Nah jadi karena kita pakai

lambangnya X ya jadi X = V * T atau V =

x/t di mana X itu adalah jarak V itu

adalah kelajuan dan t itu adalah selang

waktu Oke kalau di SD kita belajar cara

mengingatnya itu kan JKW ya JKW jarak =

kecepatan dikali dengan waktu kalau

sekarang karena kita udah belajar di

fisika SMA itu berarti kita harus paham

lambang-lambang dari jarak itu adalah x

kemudian kecepatan itu adalah V dan t

itu adalah waktu oke

Nah di sini kita lihat contohnya ya

soal nomor 1 kita lihat contohnya Sebuah

mobil bergerak lurus dengan kelajuan

berarti diketahui itu adalah

V ya V = 54

km/jam nah ini bagusnya kita rubah ya

kan kita udah pernah belajar kelas 1

dulu cara merubah satuan berarti kalau

kita rubah ke meter per sekon jadinya

ini adalah

54.000 ya per 300 3600

54 / 36 itu bisa nggak ya

bagi 9 itu 60 bagi 9 itu 4 berarti ini

jadinya 15 ya 15 meter per sekon v nya

kemudian jarak yang ditempuh berarti t t

= 5 menit ini dirubah juga ke detik

berarti 5 * 60 detik ya sama dengan

300 Detik nah yang ditanya adalah jarak

berarti jarak itu X tadi kan Nah X itu

rumusnya adalah

V * T berarti 15 * 300 berarti adalah

4500 meter ya Sehingga jawabannya adalah

yang e Oke Paham ya adik-adik Nomor 2

Jika sebuah benda bergerak lurus

beraturan berarti artinya ini adalah GL

GLB kecepatannya berarti gimana

kecepatannya tadi Berarti kecepatannya

itu tetap dan percepatannya adalah nol

ya Sehingga jawabannya adalah yang c

Nah untuk lebih pahamnya adik-adik boleh

mengerjakan soal latihan berikut ini

soal nomor 1 nah ini nanti dirubah ya

Jadi yang diketahui adalah jarak

kemudian waktunya setengah menit nah

setengah menit itu berapa Detik Nah

nanti silakan dicari sendiri ya yang

ditanya adalah kecepatan nah kecepatan

itu nanti adik-adik harus merubah ke

dalam kilometer per jam Nah jadi

inget-ingat lagi pelajaran waktu kelas 1

ya

Nah untuk lebih pahamnya silahkan kita

lanjutkan video pembelajaran berikut ini

silahkan di klik ya