Episode 19: Kinematics – The Ultimate Revision & A New Friend

The second major test was just a few days away, and I was already feeling the weight of my poor Physics scores.

Physics had always been my weakest subject, and Kinematics was a nightmare. There were so many formulas, graphs, cases—and I could never understand which one to apply in which situation.

I was sitting in my usual place in Allen Bhubaneswar’s classroom, flipping through my module, when I overheard a conversation behind me.

"Kinematics tough nahi hai. Bas sahi approach chahiye."

I turned around and saw a tall, nerdy-looking guy explaining something to his friend.

"Kinematics easy lagta hai tujhe?" I asked, genuinely curious.

He smiled. "Haan, bas concepts ko samajhna aana chahiye. Tu revision kar raha hai?"

"Haan, but physics mera weak hai."

"Chal, aaj tere saath milke poora kinematics revise karte hain."

That’s how I met Shantanu Kumar Panda—who would soon become one of my closest friends.

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Complete Kinematics Revision – Important Concepts & Formulas

That evening, we sat at a bench outside our hostel, armed with our Allen modules, past papers, and class notes.

Understanding Motion – Basics

Kinematics is the study of motion without considering forces.

Types of Motion:

✅ Uniform Motion – Constant velocity, no acceleration.

✅ Non-Uniform Motion – Changing velocity, has acceleration.

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Equations of Motion (SUVAT Equations)

For motion with constant acceleration:

1️⃣

2️⃣

3️⃣

Where:

\= Initial velocity

\= Final velocity

\= Acceleration

\= Displacement

\= Time

✅ Shortcut to Solve Questions Faster:

🚀 If time isn’t given, use

🚀 If acceleration isn’t given, use

🚀 If velocity isn’t given, use

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Projectile Motion – Nightmare Simplified

Projectile motion was my weakest area, but Shantanu broke it down beautifully.

Key Formulas:

Horizontal Motion:

x \= u_x t

v_x \= u_x ]

Vertical Motion:

y \= u_y t + \frac{1}{2} g t^2

v_y \= u_y - g t ]

v_y^2 \= u_y^2 - 2 g y

✅ Important Results:

🚀 Time of Flight:

T \= \frac{2u \sin \theta}{g}

H \= \frac{u^2 \sin^2 \theta}{2g}

R \= \frac{u^2 \sin 2\theta}{g}

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Relative Motion – Confusing But Easy

🚗 If two objects move in the same direction, relative velocity \=

🏃‍♂️ If two objects move towards each other, relative velocity \=

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Solving Real NEET-Level Questions

After finishing theory and formulas, we practiced some important NEET-level questions.

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🚀 Question 1: Find the Range and Max Height of a Projectile

A ball is thrown at 45° with velocity 20 m/s. Find the range and maximum height.

Solution:

Given:

u \= 20 \text{ m/s}, \quad \theta \= 45^\circ, \quad g \= 10 \text{ m/s}^2

Step 1: Find the Time of Flight

T \= \frac{2u \sin \theta}{g}

\= \frac{2 \times 20 \times \sin 45}{10} ]

\= \frac{40 \times \frac{1}{\sqrt{2}}}{10}

\= \frac{40}{10\sqrt{2}} \= 2.83 \text{ sec} ]

Step 2: Find the Maximum Height

H \= \frac{u^2 \sin^2 \theta}{2g}

\= \frac{20^2 \times \sin^2 45}{2 \times 10} ]

\= \frac{400 \times \frac{1}{2}}{20} \= 5 \text{ m}

Step 3: Find the Range

R \= \frac{u^2 \sin 2\theta}{g}

\= \frac{20^2 \times \sin 90}{10} ]

\= \frac{400 \times 1}{10} \= 40 \text{ m}

✅ Final Answers:

🟢 Range \= 40 m

🟢 Max Height \= 5 m

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🚀 Question 2: Find Relative Velocity

A train moving at 30 m/s sees another train moving at 20 m/s in the same direction. Find the relative velocity.

Solution:

Since both trains are moving in the same direction, relative velocity is:

V_{\text{relative}} \= V_A - V_B \= 30 - 20 \= 10 \text{ m/s}

✅ Final Answer: 10 m/s

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🚀 Question 3: Ball Thrown Vertically Up

A ball is thrown vertically upward with 20 m/s. How long will it take to reach max height?

Solution:

Using

v \= u - gt

0 \= 20 - 10t

t \= 2 \text{ sec} ]

✅ Final Answer: 2 seconds

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The Beginning of a Strong Friendship

We studied for almost 3 hours straight that night.

By the time we were done, my fear of Kinematics had reduced a little.

"Tu mast padhata hai, bhai," I said.

Shantanu grinned. "Mast padhai tab hogi jab tu test me accha karega."

That night, as I lay on my bed, I realized—

I had just found a true friend.

A study partner.

And maybe, just maybe… someone who would help me survive NEET.

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