Rahul DubeyDropperSample· 3d ago
Fridge door open makes the room hotter, COP of 9 seems odd, and fridge cooling lowers entropy. Does it break the second law?
A third-attempt student asking a first-principles question late at night.
#physics
Stories and questions with this tag.
- Commons CommunityTeam· 3d ago
My maths is weak. What is the minimum maths I actually need to survive NEET Physics?
Physics feels impossible when algebra and trigonometry feel shaky. Here is a realistic list of what you need, what you can skip, and how to build it alongside the chapters.
- Yash Tiwari11thSample· 5d ago
In an inelastic collision kinetic energy is lost, so how can momentum still be conserved?
Aaj phir ek basic doubt aaya hai bhai. Work Energy and Power, collisions part. NCERT says in all collisions the total linear momentum is conserved, but kinetic energy is conserved only in elastic collisions. Mujhe ye sam
- Ananya Reddy11thSample· 6d ago
Cross product: I can calculate it but I never know which way the answer points
I'm in class 11 PCB and we just started torque and angular momentum. I can do the arithmetic for the cross product, but I keep losing marks on direction and I think my understanding is a bit broken. What I know: \vec\tau
- Yash Tiwari11thSample· 6d ago
Geostationary satellite height fixed kyun hai, only over equator, and are astronauts really at zero gravity?
bhai Gravitation ka last part, satellites. NCERT says a geostationary satellite stays about 36,000 km above the Earth's surface, period 24 hours, orbit in the equatorial plane, and moves west to east. Mujhe 3 cheezein sa
- Siddharth RaoDropperSample· 8d ago
Rolling down an incline: why does friction not reduce the energy, and which shape reaches first?
I'm repeating, and rotational motion is the chapter I have always handled with formulas, not understanding. This time I want the concept. Pure rolling means v=\omega R for the centre. Total KE =\tfrac12mv^2+\tfrac12I\ome
- Riya Singh12thSample· 9d ago
Magnetic force does no work, yet the velocity direction changes. And what's the pitch of the helical path?
Chapter: Moving Charges and Magnetism. I'm trying to see the story in the equations, but a few lines feel like they contradict each other. The force on a charge is \vec F = q \vec v\times\vec B . It's always perpendicula
- Riya Singh12thSample· 9d ago
The teacher who made me stop being scared of physics (with a key on a thread)
A small story about a Tuesday, a pendulum, and the sentence I still carry around.
- Commons CommunityTeam· 9d ago
How much time is Semiconductors and Logic Gates actually worth? Can I just skim it?
The last Physics unit is mostly facts, circuits and truth tables. How much time does it deserve, and when in the year should you do it?
- Diya Menon11thSample· 10d ago
Reading a progressive wave equation: how do I find direction, speed, wavelength, and what is particle speed?
ahh my teacher gave this equation and I just stared at it
- Rohan Sharma11thSample· 10d ago
Projectile motion shortcuts: is H = R tanθ / 4 legit? and why do 30° and 60° give the same range?
So I've been doing projectile motion and my physics teacher said "learn the shortcuts, they save two minutes per question". Problem is he writes them on the board and moves on, and I don't know if I'm using them right. T
- Tanvi Deshmukh12thSample· 10d ago
Flux = BA cosθ, but which angle is θ? And why is emf zero when flux is maximum?
ok so I made a really neat table in my notes for Faraday's law but the very first line is breaking my brain. NCERT defines flux as \Phi B = \mathbf{B}\cdot\mathbf{A} = BA\cos\theta . In the example I solved, a coil is pl
