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1. Why catalysts affect forward and reverse reactions?

Based on the very basic understanding on enzymes I have gained from Year 12 Biology and Chemistry, I don't undesrtand why the enzymes specific shape also helps the reverse reaction. I guess my trouble would be due to the simplified diagrams I've seen from Biology, where only the forward reaction...
2. Transformer for a power supply

I am going to make a power supply. I understand the smoothing capacitor and the full-wave bridge rectifier. I am trying to make a 60V, maybe 10A power supply - maybe only 5A, but I would prefer 10A. I don't have a transformer for it, though. I have researched a fair bit on transformers...
3. Multi-layer magnet with seperate coils

I am trying to make a very strong magnet that will only last for a short pulse, just a fraction of a second, with a high peak current. I am going to use 1mm (18awg) wire, so the resistance should be pretty low, but with even just 25m, it would be expected to have 0.5Ω. I would like to have...
4. Resistance of a discharging capacitor

I am trying to calculate the maximum current drawn from a capacitor that is connected to a resistor of a very low value (a few mΩ). Because the resistor does not have a large resistance as I've seen with many V/t and I/t graphs for capacitors connected to resistors, where the decay of the curve...
5. Force from power at rest = infinity?

Force can be expressed as F = P/v where P = power (watts) and v = velocity (metres per second) So what happens when you use a given amount of power to accelerate an object from rest? This would be given by: a = P/(mv) And since v = 0 => a = P/(m*0) This would be division by 0...
6. Finding the graph formula with know points and other equation.

I have an equation for determining the acceleration of an object being propelled by a constant power source, that is affected by air resistance: a = \frac{P}{mv}-\frac{CDpAv2}{2m} Since F = \frac{P}{v} I am trying to graph this as a velocity-time graph, however, I don't know how to do it...
7. Solving for a variable, transposing equation

I have an equation, where acceleration is affected by a driving power and air resistance. The acceleration is given by: a = (2P / m + u^2)^0.5 - (k*p*A*u^2 / 2m) - u I'm trying to make "u" the subject, which is previous velocity, to find at what velocity does acceleration become 0, the...
8. Motor circuit excessive heat

I have recently pulled apart two old RC helicopters for their parts and built an RC car out of it. It is pretty basic, and uses the servo motors, motors and the receiver from the helicopter, and I control it with the controller that came with it. It works fine, except for an excessive heat...
9. Equation that integrates previous y-value.

I am making a game that has some sort of physics equations, although heavily modified to make it work better. I am trying to find the maximum velocity of a ship according to these rules/steps: thrust = ((p*r)^0.5)*10 -where r is a constant (0.04) and p is the power (3.33x10^5 in this...
10. Solving log_a(y)^n

Homework Statement I am wondering how you are meant to solve something like log_10(x)^2 = 0. What does multiplying and dividing do to the log function algebraically, I can easily tyoe into a calculator, but I don't know how to work it out on paper. My text book does not cover how to do these...
11. Creating Electric Arcs?

How can I safely produce an electric arc, preferably multiple centimetres long, the longer the better, out of some basic stuff like a transformer and a motorbike battery? I would like to produce an electric arc that is clearly visible, and that isn't dangerous, so the amperage should be quite...
12. Alternatives to electricity?

As technology has advanced, we have come up with ways to produce and use more energy, and have come up with many different ways of doing so. Most of what I know of using energy for households or factories or big machines is that they use electricity, as a way to convert fuel, heat, wind...
13. Is there current even with huge resistances?

If I had a AA battery hooked up to both my hands, positive to my right hand and negative to my left hand, I would expect the resistance to be huge, maybe in the millions of ohms? According to Ohm's Law, if you have a voltage, and the resistance is not infinite, then there is a current, no...
14. Calculating both final velocities (conservation of momentum)

How do you calculate both final velocities in an elastic collision (assuming all momentum is conserved). For example, if a 1000kg car going at 20m/s rammed into a 800kg car going at 30m/s opposite direction, what would both their final velocities be? In my year 11 physics course, we only...
15. Smaller diameter pressure outlet to increase force?

I have a hose that temporarily stores pressure in it, and it is about 19.05mm (3/4 inch). The outlet diameter is 8mm, so the air is squeezing into an area ~0.4 times the size. Does this increase the air flow speed, or the pressure? Does it follow a rule similar to: P1*V1 = P2*V2 except...
16. Projectile Motion: Formula for range for a given angle

I was watching a YouTube video on projectile motion: It says that the range is given by the formula: d = v*cosθ*t It also says that the time to reach the maximum height is given by the formula: t = \frac{v*sinθ}{a} where v*sinθ is the initial vertical velocity Well, not...
17. Affect of air resistance on a projectile

Ok, so I have calculated an ideal speed of a projectile, but now I would like to know how it is affected by air resistance, although I'm only interested in the air resistance when it's outside the barrel, hopefully that'll simplify it a bit. So the formula is: FD = \frac{1}{2}CDρAv2 Can I...
18. Ultracapacitor to power electromagnet?

I have been looking for a better way to power my electromagnet than a bunch of AA batteries, and am now thinking of using ultracapacitors. I have a few questions. I have been looking on ebay for them, I don't know of better options, and I have seen mostly 2.7V with >1F, up to 1500F. One...
19. How does momentum, inertia and drag affect the motion of an object?

How does momentum and inertia affect changes in speed, when considering acceleration from thrust, or from decelleration from drag? Say, for a fixed mass of 100kg, at a velocity of 10m/s, is a force of 10N is applied in the forwards direction, then F = ma -> a = F/m. a = 10/100, a = 0.1 m/s^2...
20. Finding strength, pull, telsa (anything) of an electromagnet

I have built a new electromagnet, my second one so far, in an attempt to make it better. I am trying to find its strength, whether that be in tesla, holding force (kg) or whatever other units there are, just so I can compare it with other magnets. What I have is a steel bolt wrapped with...
21. Resistance in circuits with transformers

I am starting to learn about transformers, and know the basics: they use electromagnetic induction to induce a current in a secondary coil, and the voltage and amperage of that second coil are dependant on the voltage and amperage of the first coil, and the ratio of turns in each coil. So...
22. Getting high current from AA batteries

I am trying to increase the strength of my electromagnet, at the moment by increasing the amperage. I have been using an old 12V motorcycle battery, but also tried with 10 AA batteries. I was wondering how I could connect the AA batteries to get a high current, so hopefully a stronger...
23. How to find the strength of an electromagnet

I have created a simple electromagnet that is just an iron railroad spike with some thick insulated wire wrapped around it. This is connected to a dodgy, old motorbike battery (I'm thinking of being a decent battery...). I have looked up how you measure the strength, but I'm not sure what is...
24. Finding speed of projectile propelled by pressurised air

I have a projectile of 4 grams, an air tank of 120 psi, a barrel length of 80 centimetres and a barrel diametre of 8 millimetres. I would like to find the ideal speed (muzzle velocity) that the projectile would be launched at, not taking into account the pressure drop, friction atmospheric...
25. Speed limit of pressurised air

How fast can air go when under pressure? Is there a formula that describes this. I was just wondering how much faster air can go when put under more pressure. Also, what is the acceleration rate of the air?
26. Seeing into the past through a mirror going fater than the speed of light.

I'm not sure if this is the correct area to post this question, but I don't know where else it could go. If it is incorrect, can someone please move it to the correct area if that is possible. This is a purely hypothetical question, and I am by no means good at physics (just starting out)...