FISIKA KELAS X: GERAK LURUS (PART 3) Gerak Vertikal ke Atas, ke Bawah, dan Jatuh Bebas

Yusuf Ahmada

8 Sept 202011:13

Summary

TLDRThis educational video script delves into the physics of vertical motion, specifically focusing on the concepts of uniformly accelerated motion (GLBB) in both upward and downward directions. It explains the equations governing these motions, including the effects of gravity, and provides examples to illustrate the principles. The script also covers the special case of free fall, emphasizing the absence of initial velocity and the acceleration due to gravity. The summary includes a problem-solving approach to calculate maximum height and time for an object thrown upwards, as well as the velocity of a stone hitting the ground after free fall from a tower.

Takeaways

📚 The video is a physics lesson for 10th graders, focusing on vertical motion, specifically free-fall and projectile motion with upward and downward directions.
🚀 The script explains the concept of vertical upward motion (GTA) with initial velocity and acceleration due to gravity, leading to a maximum height where velocity becomes zero.
📉 The formula for vertical upward motion is given as \( V^2 = v_0^2 + 2as \), where \( V \) is the final velocity, \( v_0 \) is the initial velocity, \( a \) is the acceleration due to gravity, and \( s \) is the displacement.
🔢 An example problem is provided to calculate the maximum height and time taken for an object thrown upwards with an initial velocity of 10 m/s.
⏱ The time to reach the maximum height in vertical motion is calculated using the formula \( t = \frac{v_0}{g} \), where \( g \) is the acceleration due to gravity.
💥 The script moves on to discuss vertical downward motion (VB), which includes the concept of free fall (GVB) with no initial velocity and acceleration due to gravity.
📌 The formula for free fall is \( V^2 = 2gh \), where \( h \) is the height from which the object falls, and \( g \) is the acceleration due to gravity.
📐 The script emphasizes the importance of understanding the direction of displacement in vertical motion, especially for downward motion starting from the point of release.
📚 The lesson includes the formula for calculating the velocity of an object at impact when it falls freely from a certain height.
🤔 The video encourages students to remember the formulas and concepts for both vertical upward and downward motion, as they are crucial for solving physics problems.
👋 The video concludes with a reminder to like, share, and subscribe for more educational content, and a farewell from the host, Yusuf Ahmad.

Q & A

What is the topic of the video?
-The video discusses the concept of vertical motion in physics, specifically focusing on the equations and examples of uniformly accelerated motion (GLBB) in vertical upward and downward directions.
What are the two types of vertical motion covered in the video?
-The two types of vertical motion covered are vertical upward motion (GTA) and vertical downward motion (VB).
What is the formula used for vertical upward motion with deceleration?
-The formula used for vertical upward motion with deceleration is \( V^2 = v_0^2 - 2gH \), where \( V \) is the final velocity, \( v_0 \) is the initial velocity, \( g \) is the acceleration due to gravity, and \( H \) is the height.
What is the maximum height reached by an object in vertical upward motion?
-The maximum height reached by an object in vertical upward motion is when its velocity becomes zero, which can be calculated using the formula \( H = \frac{v_0^2}{2g} \).
How is the time taken to reach the maximum height in vertical upward motion calculated?
-The time taken to reach the maximum height in vertical upward motion is calculated using the formula \( t = \frac{v_0}{g} \).
What is the acceleration for vertical downward motion?
-The acceleration for vertical downward motion is the acceleration due to gravity, denoted as \( g \).
What is the formula for vertical downward motion with initial velocity?
-The formula for vertical downward motion with initial velocity is \( V^2 = v_0^2 + 2gH \).
What is the term for vertical downward motion without initial velocity?
-The term for vertical downward motion without initial velocity is free fall (GVB).
How is the velocity of an object in free fall calculated at the moment of impact?
-The velocity of an object in free fall at the moment of impact is calculated using the formula \( V = \sqrt{2gH} \).
What is the significance of the formula \( H = \frac{1}{2}gT^2 \) in the context of the video?
-The formula \( H = \frac{1}{2}gT^2 \) is used to calculate the height an object has fallen in free fall, where \( H \) is the height, \( g \) is the acceleration due to gravity, and \( T \) is the time of fall.
What is the purpose of the example problems provided in the video?
-The example problems are provided to illustrate the application of the formulas for vertical motion and to help viewers understand how to solve practical physics problems involving these concepts.

Outlines

00:00

📚 Introduction to Vertical Motion in Physics

This paragraph introduces the topic of vertical motion in physics, specifically focusing on the concepts of uniformly accelerated linear motion (GLBB) with vertical ascents and descents. It explains the motion of an object thrown upwards against gravity, using the initial velocity, acceleration due to gravity, and the maximum height reached as key parameters. The equations of motion are discussed, including the time to reach the maximum height and the final velocity becoming zero at the peak. An example problem is presented to calculate the maximum height reached by an object thrown upwards with an initial velocity of 10 meters per second.

05:00

🔍 Detailed Analysis of Vertical Ascending and Descending Motion

The second paragraph delves deeper into the physics of vertical motion, contrasting the upward motion with the downward motion towards the center of the Earth. It discusses the equations for uniformly accelerated motion with varying signs for acceleration, depending on whether the motion is against (decelerating) or with (accelerating) gravity. The paragraph also covers the concept of free fall (GVB), where an object falls from rest under the influence of gravity alone. An example is given to calculate the velocity of a stone when it hits the ground after being dropped from a 40-meter tall tower, using the equations of motion for free fall.

10:05

🎓 Conclusion and Encouragement for Further Learning

The final paragraph wraps up the discussion on vertical motion, summarizing the key concepts covered in the video and encouraging viewers to apply these concepts to solve physics problems. It also invites the audience to like, share, and subscribe for more educational content. The presenter, Yusuf Ahmad, ends the video with a thank you note and a traditional greeting, emphasizing the usefulness of the video and looking forward to future educational videos.

Mindmap

Keywords

💡GLBB

GLBB stands for Gerak Lurus Berubah Berat, which translates to 'Variable Acceleration Straight-Line Motion' in English. This concept is central to the video's theme as it discusses the physics of motion, particularly in the context of vertical motion. In the script, GLBB is used to describe the motion of objects that are either decelerating as they move upward (slowing down due to gravity) or accelerating as they fall downward (speeding up due to gravity).

💡Vertical Motion

Vertical motion refers to the movement of an object in a direction perpendicular to the ground, either upwards or downwards. This is a key concept in the video as it focuses on the physics of objects moving vertically, such as when thrown upwards or falling downwards. The script provides examples of vertical motion, including calculating the maximum height reached by an object thrown upwards and the velocity of an object when it hits the ground after falling from a certain height.

💡Acceleration Due to Gravity

Acceleration due to gravity, often denoted as 'g', is the rate at which objects accelerate towards the Earth when in free fall. In the video, this concept is used to explain the acceleration of objects in vertical motion, particularly in the context of GLBB. The script mentions that the acceleration due to gravity is used in the equations to calculate the final velocity and the distance traveled by objects in vertical motion.

💡Initial Velocity (v0)

Initial velocity, represented as 'v0', is the speed at which an object starts moving. The video discusses how initial velocity affects the trajectory and final position of objects in vertical motion. For instance, the script uses initial velocity in the equations to determine the maximum height an object reaches when thrown upwards.

💡Final Velocity (VT)

Final velocity, denoted as 'VT', is the speed of an object at the end of its motion. In the context of the video, final velocity is crucial for understanding the outcomes of vertical motion, such as the velocity of an object when it reaches its maximum height or when it hits the ground after falling. The script includes examples where final velocity is calculated using the equations of motion.

💡Deceleration

Deceleration is the reduction in the speed of an object. In the video, deceleration is discussed in the context of an object moving vertically upwards, where the object slows down due to the force of gravity until it reaches its maximum height and its velocity becomes zero. The script explains this concept using the equation VT = v0 - gt, where 't' is time and 'g' is the acceleration due to gravity.

💡Free Fall (GVB)

Free fall, or 'GVB' in the script, refers to the motion of an object falling under the influence of gravity alone, without any initial velocity. This concept is important in the video as it illustrates a specific type of vertical motion where the object starts from rest and accelerates due to gravity. The script provides an example of calculating the velocity of a stone in free fall from a tower.

💡Equations of Motion

The equations of motion are mathematical formulas used to describe the behavior of moving objects. In the video, these equations are essential for calculating various aspects of vertical motion, such as final velocity, time taken to reach a certain height, and the maximum height reached. The script presents several equations, such as VT = v0 - gt and VT^2 = v0^2 - 2gh, which are used to solve problems related to vertical motion.

💡Maximum Height

Maximum height is the highest point reached by an object in its trajectory, particularly in vertical motion. The video discusses how to calculate the maximum height using the equations of motion, which is relevant when an object is thrown upwards and comes to a stop at its peak before falling back down. The script includes a problem where the maximum height is calculated using the formula H = v0^2 / (2g).

💡Time to Reach Maximum Height

Time to reach maximum height is the duration it takes for an object to reach the highest point in its vertical motion. This concept is discussed in the video in the context of solving problems where the time required for an object to reach its peak after being thrown upwards is needed. The script uses the equation t = v0 / g to find the time to reach the maximum height.

Highlights

Introduction to the physics of vertical motion in class 10, continuing from previous discussions on free fall and projectile motion.

Explanation of vertical motion upwards (GTA) with initial velocity and acceleration due to gravity.

Illustration of an object being thrown upwards, slowing down until it reaches its maximum height with zero velocity.

Equations for vertical motion upwards: v = v_0 - gt and h = v_0t - 1/2gt^2.

Discussion on the use of minus sign in equations for decelerated vertical motion upwards.

Introduction to vertical motion downwards (VB) with gravity as the only acceleration.

Equations for vertical motion downwards: v = v_0 + gt and h = v_0t + 1/2gt^2.

Differentiation between accelerated and decelerated vertical motion in the context of gravity.

Concept of free fall (GF) as a special case of vertical downward motion with zero initial velocity.

Equations for free fall: v = gt, h = 1/2gt^2.

Example problem: Calculating the maximum height reached by an object thrown upwards with an initial velocity of 10 m/s.

Solution to the example problem using the equation h_max = v_0^2/2g.

Determination of the time taken to reach the maximum height in vertical motion upwards.

Explanation of why the velocity at the maximum height is zero in vertical motion upwards.

Example problem involving a stone dropped from a 40m high tower and calculation of its impact velocity.

Use of the equation v^2 = 2gh to find the velocity of the stone when it hits the ground.

Conclusion summarizing the concepts of vertical motion, including upwards and downwards motion, and free fall.

Call to action for viewers to like, share, and subscribe for more educational content.