LESSON–3 : MOTION IN A PLANE
ADDITIONAL MATERIALS – 9 (PART–2)
IIT PYQs – METHODS, TRICKS & SOLVE PROCEDURE
🔹 PYQ–11 (JEE ADVANCED – METHOD SELECTION)
Question:
A projectile is thrown with speed u at angle θ.
Find the speed of the projectile at half the maximum height.
Correct Method:
- Use energy conservation
- Avoid equations of motion (saves time)
Solution:
At maximum height: vertical velocity = 0
Half maximum height ⇒ loss in potential energy = (1/2)mgh
So kinetic energy reduces partially, not completely.
Trick:
Whenever height-related speed is asked → use energy method.
🔹 PYQ–12 (JEE MAIN – HOW TO THINK)
Question:
A body is projected horizontally from a height h.
Find the time taken to reach the ground.
Solving Procedure:
- Ignore horizontal motion completely
- Consider only vertical fall
- Apply h = ½gt²
Answer:
t = √(2h / g)
Exam Trick:
If horizontal velocity is given but height is asked → horizontal data is a trap.
🔹 PYQ–13 (JEE ADVANCED – RANGE THINKING)
Question:
For which angle of projection is the range of a projectile maximum?
Procedure:
- Recall R = (u² sin2θ)/g
- Maximum value of sin function = 1
Answer:
θ = 45°
Shortcut:
Maximum range → 45° (no calculation needed).
🔹 PYQ–14 (JEE ADVANCED – RELATIVE VELOCITY METHOD)
Question:
Two particles move in perpendicular directions with speeds v₁ and v₂.
Find relative speed.
Correct Method:
- Check angle between velocities
- Apply Pythagoras theorem
Answer:
Relative speed = √(v₁² + v₂²)
Trick:
Perpendicular → directly apply √(v₁² + v₂²)
🔹 PYQ–15 (JEE MAIN – SPEED AT SAME LEVEL)
Question:
Compare the speeds of a projectile at two points on its path
at the same vertical height.
Method:
- Use energy conservation
- Same height ⇒ same potential energy
Answer:
Speeds are equal.
Shortcut:
Same height → same speed (ignore direction).
🔹 PYQ–16 (JEE ADVANCED – COMMON TRAP)
Question:
At the highest point of projectile motion, which quantities are zero?
Correct Thinking:
- Vertical velocity = 0 ✔
- Horizontal velocity ≠ 0 ✖
- Acceleration ≠ 0 ✖
Exam Tip:
Never assume acceleration becomes zero.
🔹 PYQ–17 (JEE MAIN – VECTOR ANGLE)
Question:
Find angle between vectors (a, b) and (b, −a).
Method:
Dot product = ab + b(−a) = 0
Answer:
Angle = 90°
Trick:
(a, b) and (b, −a) are always perpendicular.
🔹 PYQ–18 (JEE ADVANCED – WHEN TO DRAW DIAGRAM)
Question:
Why is drawing a diagram important in projectile motion problems?
Answer:
Diagram helps to:
- Separate x and y motions
- Avoid sign mistakes
- Identify symmetry
🔹 PYQ–19 (JEE ADVANCED – FINAL LOGIC TEST)
Question:
Can the magnitude of velocity of a projectile ever increase
during upward motion?
Answer:
No. During upward motion, speed continuously decreases.
🧠 UNIVERSAL IIT PROBLEM SOLVING PROCEDURE
- Read question twice
- Draw a rough diagram
- Identify motion type (x, y, or vector)
- Choose method (Equations / Energy / Geometry)
- Solve step-by-step
- Check units & physical sense
✅ ADDITIONAL MATERIALS – 9 (PART–2) COMPLETED
(Method mastery + exam intelligence)
Intermediate Physics Complete Notes – IIT JEE & Board Exams
This page contains complete Intermediate Physics notes along with IIT JEE materials, previous year questions, solved problems, diagrams, and exam strategies.
📘 Lesson 1: Units and Measurements
📘 Lesson 2: Motion in a Straight Line
📘 Lesson 3: Motion in a Plane
- Part 1
- Part 2
- Part 3
- Part 4
- Part 5
- Part 6
- Part 7
- Part 8
- Part 9
- Part 10
- Part 11
- Part 12
- Part 13
- Part 14
- Part 15
- Part 16
- Part 17
📌 This page is updated regularly with new lessons.
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