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What is the topic of the first lesson in quarter four of grade nine science?
What is the learning objective of the first topic covered in the grade nine science lesson?
What is the second law of motion according to Newton?
What is Newton's second law of motion?
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What is the relationship between net force and acceleration according to the second law of motion?
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When can we say that there is constant acceleration?
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When can we say that there is constant acceleration?
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What is a speedometer?
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What is the difference between speed limits on highways and speed limits on small avenues and streets?
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What is a speedometer used for in a vehicle?
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What is the definition of acceleration?
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What is the definition of acceleration?
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What is UAM?
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What is the difference between uniform and non-uniform acceleration?
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What is the role of traffic enforcers in maintaining the flow of traffic?
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What is the difference between constant and non-uniform acceleration?
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Study Notes
Good day, students! Welcome back to Ma Estrang Techie's YouTube channel. We are now in quarter four of our grade nine science lesson, and the first topic we are going to cover today is all about the horizontal and vertical motions of a projectile. Our learning objective is to describe the horizontal and vertical motions of a projectile. Get ready to learn this lesson, so keep on watching!
In grade 8, you learned about Newton's second law of motion, the law of acceleration. According to this law, the net force is equal to the product of the mass of an object and its acceleration. Let's have a simple activity to refresh your mind. State the second law of motion by completing this paragraph.
The second law of motion is the law of acceleration. The acceleration of an object, as produced by a net force, is directly proportional to the magnitude of the net force in the same direction as the net force and inversely proportional to the mass of the object. That is the second law of motion.
Great job, class! It's good that you can still recall the law of acceleration. Always remember that the larger the force applied to an object, the larger its acceleration. Usually, the acceleration of a body may change and vary from time to time due to several factors. If that is the case, when can we say that there is constant acceleration?
Let's have a review about uniformly accelerated motion or UAM. Look at the picture shown on your screen. Are you familiar with these blue uniformed men who are usually positioned in busy streets? They are the traffic enforcers who play a crucial role in maintaining the flow of traffic and implementing laws and regulations on the road that every motorist should follow. Speed limits are observed on roads, and they vary and depend on several conditions. Speed limits for highways are different from speed limits on small avenues and streets. This prevents vehicles from speeding up or accelerating unnecessarily in our busy streets as they are being monitored by traffic enforcers.
Acceleration is defined as the rate of change in velocity with time. It is a vector quantity having both magnitude and direction. The acceleration of vehicles usually changes from time to time. A vehicle may speed up as it travels to highways or slow down as it approaches an intersection. It should also stop when the stoplight is red and eventually accelerate when the light turns green. We can say that most types of acceleration that we observe are not constant or non-uniform due to these factors.
When you are riding a vehicle, you can say that it speeds up or slows down based on its speedometer. A speedometer indicates the speed of a vehicle. It is usually combined with a device known as an odometer, which records the distance traveled. Assume that you are riding a vehicle and observe these speedometer readings. What can you say about the readings on the speedometer during each minute? What can you infer from the data in the table?
This means that the vehicle speeds up every minute, and there is a one kilometer per hour increase in the speed of the vehicle for every minute. The increase for every minute is constant; therefore, we can say that the vehicle has uniform acceleration. This vehicle exhibits a uniform or constant acceleration. It is a type of motion in which the velocity of an object changes by an equal amount in every equal time period.
Just like these examples in uniformly accelerated motion or UAM, the value of the acceleration is constant. The velocity changes but at a
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Description
Test your knowledge on the laws of motion and uniformly accelerated motion with Ma Estrang Techie's latest quiz! This quiz will cover topics such as Newton's second law of motion, acceleration, and uniform acceleration. You will be challenged to recall important concepts and apply them to various scenarios. Improve your understanding of science and physics by taking this quiz now!
