Hi! I'm a koala
Why is period not dependant on amplitude? Is it because as amplitude increases, strain energy increases, and the strain energy will be converted to kinetic energy hence v is just made to be larger so it moves faster to oscillate at the same period? is this correct/logical?1 AnswerPhysics2 weeks ago
Why is specific latent heat = (rate of supply of energy)/(rate of loss of mass) ??
if we plot a graph of Q vs m, the gradient is L
but if we heat water with a constant power P in a time of t and plot a graph of mass vs time, then why is L = (rate of supply of energy)/(rate of mass loss) ?
I understand that Q=Pt, so it takes Pt amount of energy to reduce the mass from m1 to m2 in a time of t. But I'm not sure why the formula is like that? I didn't think m here works like the ∆T in Q=mc∆T, or does it?1 AnswerPhysics2 weeks ago
if period of oscillation is not dependent on amplitude, then how come for simple harmonic motion we have
which means acceleration is dependent on x which is displacement (basically amplitude) so period clearly depends on amplitude based on this equation?2 AnswersPhysics2 weeks ago
If the piston in a bicycle pump is pushed inwards but the temperature is kept constant, then more molecules will hit the piston in each second
but why will each collision produce the same force? "more molecules will hit the piston each second" shouldn't that mean F increases? I know that v is kept constant here because T is kept constant.3 AnswersPhysics3 weeks ago
I learnt that the huge air pressure around us does not crush us because the air inside our bodies presses outwards with an equal and opposite force.
But I don't understand. Newton's third law says the forces must act on different objects.
So the forces are
1. Outside air on body
2. Air inside body on outside air
So since they act on different object, the force of the outside air on the body cannot be "cancelled out" by the force of the air inside the body on the outside air. So why do we not collapse under air pressure? The text made it seem like the forces cancel out, I'm very confused!
Thank you6 AnswersPhysics3 weeks ago
when an object falls under gravity, I understand that the air resistance increases with speed, and since velocity is increasing with time (decreasing gradient because of air resistance) the air resistance on the object increases with time too and they will eventually cancel each other out. So is this why the air resistance can never be higher than the weight of the object (or else the object would start flying after reaching terminal velocity)? Because air resistance is proportional to speed, at terminal velocity speed is constant so air resistance cannot get higher. True?8 AnswersPhysics1 month ago
I learnt that a helicopter lifts because of Newton's third law. Its blades pushes the air below it with a force F and simultaneously the air pushes the helicopter upwards with the same force F.
Since F=ma, then the helicopter experiences acceleration F/m.
Is this true?1 AnswerPhysics2 months ago
I thought of it like this
from the first law of thermodynamics ∆U=q+w
since gas is compressed and no heat is provided to the system, q=0 and there is work done on the s
ystem, so +w
so ∆U=+w hence there is a rise in temperature of the gas (since internal energy U is a function of temperature)
so since temperature is the measure of kinetic energy of molecules, hence there is rise in kinetic energy too?
Or from the fact that there is work done on the system,
work done converted into kinetic energy
so there is increase in kinetic energy
is my logic correct? or can someone explain it better?4 AnswersPhysics2 months ago
Boyle's law states pV= constant provided the temperature of the gas remains constant.
But the first law of thermodynamics ∆U=q+w tells us that when a gas is compressed there is ∆U hence a rise in temperature.
So what am I missing here? How is Boyle's law consistent with this first law of thermodynamics?2 AnswersPhysics2 months ago
By the way, I'm talking about the medical face mask (the one with a blue side and a white side).
I can't find a solid answer from the internet. One source said that face masks are only effective in protecting others from you if you have the virus, but it does not protect you from other people if other people aren't wearing a mask. Meaning it's hard for particles to leave the mask, but easy for particles to enter the mask?
If the mask stops particles from your mouth leaving the mask which you wear, then shouldn't that mean that the mask should be able to also prevent particles from outside the mask from entering? Why is it only one-way?
And another question is it any different from a fabric mask?
Thanks. Very confused.15 AnswersMedicine2 months ago
My opinion: The only good rationale behind the criminalisation which I found is that it is for those who use suicide as an easy escape to avoid their other punishment(s), which in turn will make them face heavier repercussions.11 AnswersLaw & Ethics9 months ago
Just name one country and please don't say some sh*t like "eVeRy CoUntRy iS GoOD iN ThEiR OwN WaY"18 AnswersPolls & Surveys10 months ago
Find the coefficient of x^(-16) in the expansion of (x^2 - 1/x)^25
Please show different methods of solving this, thanks in advance5 AnswersMathematics1 year ago