# Recent content by coconut62

1. ### Conceptual question regarding buoyant force

I think I got it: For all three fluids, weight of fluid displaced is the same, but Weight = mg = (rho)(V)g Therefore rho is inversely proportional to V. For the fluid of highest density, volume displaced is the least, because just a small volume of this fluid already weights the same as a...
2. ### Conceptual question regarding buoyant force

A penguin floats first in a fluid of density p0, then in a fluid of density 0.95p0, and then in a fluid of density 1.1p0. a) Rank the densities according to the magnitude of the buoyant force on the penguin, greatest first. b) Rank the densities according to the amount of fluid displaced by the...
3. ### Conceptual problem regarding pressure and surface area

Is the air pressure acting on the top of the head of a person standing in a room equal to the air pressure acting on a same area on the floor of the same room? Since F = pA , it seems as if the air pressure is independent of the height of the surface on which it is acting. But that doesn't seem...
4. ### Conservative force and potential energy

U = - integrate [0 to 2] F(y) = - integrate [0 to 2] (3y-6) = (3/2)y^2 - 6y. Substituting the limits I get 6J. Is that correct?
5. ### Conservative force and potential energy

Problem: A conservative force F is acting on a particle that moves vertically. F can be expressed as (3y-6) j head N, y is in m and j head is a unit vector along vertical direction. a) Calculate the potential energy associated with F, with the potential energy set to zero at y=0. b) At what...
6. ### Effects of frequency on rate of emission of photoelectrons

Shouldn't the photon rate be constant? I thought it is just the <energy> of the photons that is increasing.
7. ### Effects of frequency on rate of emission of photoelectrons

But why does the book say rate of emission decreases when frequency increases?
8. ### Effects of frequency on rate of emission of photoelectrons

Light of constant intensity is incident on a metal surface, causing electrons to be emitted. State and explain why the rate of emission of electrons changes as the frequency of the incident light is increased. My answer: As frequency increases, energy of photons also increases, so more energy...
9. ### SHM of liquid in U tube

The figure shows a U tube of uniform cross-sectional area A containing liquid of density p. The total length of the liquid column is L. When the liquid is displaced by an amount x from its equilibrium position, it oscillates with simple harmonic motion. The weight of liquid above AB provides...

Thanks.
11. ### Hypothesis test (binomial) problem

Homework Statement Hester suspected that a die was biased in favour of a four occuring. She decided to carry out a hypothesis test. When she threw the die 15 times, she obtained a four on 6 occasions. Carry out the test, at the 5% level, stating your conclusion clearly. Homework...
12. ### Arrangement of eigenvalues in a Diagonal matrix

Homework Statement Is it necessary to arrange the eigenvalues in increasing value order? As shown in the image attached, if I arrange my eigenvalues -2, -1, 1 diagonally, my D would be 2^8 , 1, 1 diagonally. However if i arrange it as, say, -1, 1, -2, my D would be different...
13. ### Statements regarding Brownian motion experiment

Do you mean that when there are less smoke particles, the probability of one particle being bombarded by gas molecules increase so its change of speed increases?
14. ### Distance from sources of different intensity to get same loudness

I think this is the formula needed: Intensity = Power/4∏r^{2} So the intensity of the sound where the person stood was P/256∏. It is now halved. So the power gets halved too. P= 128∏I since P = 4∏r^{2}I 128∏I=4∏r^{2}I r=4√2 Please correct me if I'm wrong.
15. ### Statements regarding Brownian motion experiment

The experimenter wanted to observe the motion of the smoke particles? Apart from smoke there's air molecules in the jar. Regarding my concern about choice A), I think the gas molecules means air molecules?