Class 9th · Physics · Chapter 2
Chapter 2: Kinematics
Chapter 2 of the Punjab Board Class 9th Physics textbook runs from page 28 to 51 and covers 9 topics. Its exercise has multiple choice questions, comprehensive questions and numerical problems. Open any of those pages in GenZ Books, tap a question, and the answer is worked from this chapter.
Open Chapter 2 of Physics in GenZ Books
The same Class 9th textbook, page for page. Tap any question and get the answer worked from that chapter — English and Urdu.
What you will learn
- Differentiate between scalar and vector quantities: [A scalar has magnitude (size) only and that a vector quantity has magnitude and direction. Students should be able to represent vectors graphically]
- Justify that distance, speed, time, mass, energy, and temperature are scalar quantities
- Justify that displacement, force, weight, velocity, acceleration are vector quantities
- Determine graphically, the resultant of two or more vectors
- Differentiate between different types of motion [i.e; translatory, {linear, random, and circular); rotatory and vibratory motions and distinguish among them.] 0
- Differentiate between distance and displacement, speed and velocity, (on
- Define and calculate average speed [average speed = (total deh travelled)/ (total time taken)]
- Differentiate between average and instantaneous speed epee shown by speedometer of a vehicle is the speed at any instant.)
- Differentiate between uniform velocity and non ا- uniferny ۳ Define and calculate acceleration [Includes deriving the Units of acceleration as ms” from the formula a = Av/At and using the formula to salve problerns. This also includes knowing that th
Topics in this chapter
- 2.1Scalars and Vectorsp. 29
- 2.3Types of Motionp. 33
- 2.4Distance and Displacementp. 34
- 2.6Accelerationp. 36
- 2.7Graphical Analysis of Motionp. 38
- 2.8Gradient of a Distance-Time Graphp. 41
- 2.10Gradient of a Speed-Time Graphp. 43
- 2.11Area Under Speed-Time Graphp. 43
- 2.13Free Fall Accelerationp. 45
Exercise
- Multiple Choice Questionsp. 48
- Comprehensive Questionsp. 50
- Numerical Problemsp. 51
A sample answer from GenZ Books
Explain · page 31: Resultant Vector
Hey there! Let's break down what a Resultant Vector (حاصل ویکٹر) is.
When you combine two or more pushes or pulls (which are vectors), the resultant vector is like a single, overall push or pull. This single vector has the exact same effect as all the individual vectors combined.
Here's what you need to know about it:
- Combination: It's the single vector you get when you add two or more individual vectors together.
- Equivalent Effect: This resultant vector acts as if it's doing the job of all the original vectors combined. It produces the same overall outcome.
- Magnitude and Direction: Just like any vector, the resultant vector has both a magnitude (مقدار) (how strong or big it is) and a direction (سمت) (where it points).
- Vector Addition: Finding the resultant vector involves vector addition, which is different from simply adding numbers (scalar addition) because you must consider directions.
Imagine you're at the local bazaar, and you and your friend are trying to push a heavy cart. You push with a certain force in one direction, and your friend pushes with another force in a slightly different direction. The resultant vector would be the single, overall force that actually moves the cart. It tells you exactly how hard the cart is being pushed and in what final direction it will move, as if only one person was pushing it with that specific force.
The biggest mistake students often make is treating vector addition like simple number addition (scalar addition). For example, if you push a box with 5 N to the right and someone else pushes it with 3 N to the left, the resultant force isn't $5 \text{ N} + 3 \text{ N} = 8 \text{ N}$. Instead, you have to consider the directions, so the resultant force would be $5 \text{ N} - 3 \text{ N} = \mathbf{2 \text{ N to the right}}$. Always remember that both magnitude and direction are crucial for vectors.
While you'll learn graphical methods like the head-to-tail rule to find it, the concept of a resultant vector is fundamental to understanding how multiple forces or velocities combine.
In short: The resultant vector is the single vector that represents the combined effect of two or more individual vectors.
AI-generated from the chapter text by GenZ Books. It can make mistakes — check it against your textbook and your teacher.