Ruben
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Relationship between stopping potential and work function
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4 votes

The work function, $\phi$ is the amount of energy required to free the electron from the pull of the nuclei of the atoms of the photosurface. Here $\phi=3\text{ eV}$. Since the kinetic energy of ...

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Is there such a thing as instantly stopping?
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4 votes

To stop instantly, you would need infinite deceleration. This in turn, requires infinite force, as demonstrable with this equation: $$\vec F=m\vec a$$ So when you hit a wall, you do not instantly stop ...

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The velocity of light changes from one medium to another, but does its energy change?
3 votes

The energy of a photon (which I presume you are referring to) is given by: $$E=hf$$ Since the frequency does not change when light transfers from medium to medium, and Planck's constant is... constant,...

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Does an object slow down after acquiring terminal velocity?
3 votes

Terminal velocity is the speed at which the drag force equals $mg$; hence, the object will remain at that speed. That said, there will be slight fluctuations because of the increasing strength of ...

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What is responsible for cutting an apple: pressure or force?
3 votes

You can have a lot of force, but that does not necessarily mean you can cut the apple. Remember that $$P=F/A$$ So if you have a sharp knife you only need a small force because the pressure will be ...

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How much water from ice and after how much time?
3 votes

First: There is $8\ \text{cm}^3$ of ice, and with a density of about $0.92\ \text g/\text{cm}^3$; hence, the total mass is $7.36\ \text g$. Since the density of water is about $1.00\ \text g/\text{...

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Protons (as opposed to neutrons) to mediate nuclear fission?
2 votes

I presume you are referring to process of nuclear fission of uranium-235, which has the equation: $$^1_0\text{n}+^{235}_{\ \ 92}\text{U}\longrightarrow ^{236}_{\ \ 92}\text{U}$$ However, a subsequent ...

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How much force is required to compress air?
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2 votes

The state from $1\text{ atm}$ to $2\text{ atm}$ is normally called decompression or contraction. An equation you can use going from one state to the next is: $$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$$ ...

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Acceleration Power
2 votes

No, it is not correct. Let $a$ be acceleration; $F$ force; $m$ mass; $v_0$ initial velocity; $v_f$ final velocity; $P$ power required; $x$ distance travelled and $t$ time taken. Hence, $$P=\frac{Fs}{t}...

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Two tensions in massless string
2 votes

The natural tendency of a rope is to move to the lowest possible tension. When an object hangs onto a rope, it slides down to the lowest possible point, at which the tension is uniform. Now, ...

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The effect of high frequency AC current in a fresh corpse
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2 votes

This article is very good in describing the dangers of electricity, which I suggest you read. http://www.allaboutcircuits.com/vol_1/chpt_3/4.html To summarise the article, $20\text{ mA}$ for $60\text{...

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Minimum power to pull a sheet of paper
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1 votes

The sum of the torques is zero, $\sum \tau =0$. Thus, since the centre of mass is in the middle of the pole, that's where the weight $W$ will act. $F_y$, is the normal force exerted by the pole on the ...

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Basics of Current Electricity
1 votes

Regarding questions one and two, I recommend that you search up how a battery works. But in essence, ions flow in the battery, whilst electrons are routed through the wire to do useful work. This is ...

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Energy, time and force
1 votes

The force is only applied for that distance, the fact that it is the same implies that the smaller object will have lower speed. Note that the relation does not imply the distance the object will move;...

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Rotational Velocity and Rotational Frequency
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1 votes

There exists indeed a subtle difference, and are often referred to as angular frequency and angular velocity. Both are $\omega$ and have units $\text{s}^{-1}$. The difference lies in the fact that ...

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Does the tension of a rope/cable change if acceleration/velocity changes?
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1 votes

Yes, you are correct in stating that the tension will be higher. In fact, it is simply: $$T=mg+ma$$ It is important however, to make the distinction between tension and the maximum tensile strength. ...

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Is rotational motion conditioned to a central force?
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1 votes

The only force in acting on bodies in circular motion is the centripetal force, equal to $$F=\frac{mv^2}{r}$$ The centripetal force acts to the centre of the rotating body; there is no such thing as a ...

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Does heat increase the volume of a gas, and in turn its pressure?
1 votes

The system will eventually reach thermal equilibrium so heat received by the gas is the same as heat lost by the container. So: $m c (T_f-T_i) + m c(T_f-T_i) = 0$. Hence you need to know the specific ...

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How much up will an object of mass $m$ will be vertically lifted if a constant acceleration $a$ is given so that resulting force is more than weight?
1 votes

Like you said, the net force of the body keeps increasing, so the body does not have constant acceleration. However, keep in mind that the body will eventually approach the speed of light. That said, ...

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Would adding water after heating decrease the overall heat, when compared to adding the water before heating for the same period of time?
0 votes

A microwave works by dielectric heating, where an oscillating high frequency electric field causes polar molecules to align in the field. Since the field alternates, they will rotate continuously ...

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Pulley problem with two masses
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We have two different masses attached to the same rope, meaning that their acceleration will be the same. Also, tension is equal throughout the rope, meaning that is the same as well. When we consider ...

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Block on an incline moving right with an acceleration
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NOTE: The blockquotes only apply with a gradual increase in acceleration starting from $0\ \text m\text s^{-2}$. The trajectory that it makes depends almost entirely on the coefficient of friction ...

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Would a three wheeled vehicle be faster than a four wheeled vehicle of the same weight?
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Friction is what keeps the wheels from spinning (i.e. traction), the friction that you want to reduce in order to gain speed, is air resistance. Removing a wheel adds more strain (friction) to the ...

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Force from solenoid
-2 votes

The interior of a solenoid the magnetic field is uniform in magnitude and direction and is given by: $$B=\mu_0 \frac{NI}{L}$$ Where $N$ is the number of turns, $L$ the length of the solenoid and $I$ ...

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