David M

I guess the power limit of an induction motor is limited by how much current the windings can take without heating up too much. Those maximum amps, the supply voltage, and power factor can be used to calculate the power the motor is using.

What I am unclear of is what happens when the frequency of the power supply to the motor is increased with a VSD.

Specifically I have a 75kW motor running at about 80% load on a 50Hz 400 volt supply.

If the frequency was increased to 77 Hz, would the motor be rated at a higher power and if so what would the new power be?

Hypothetically if the sun exploded in such a way that half its mass took off to the left (west) at close to the speed of light and similarly half to the right so as to spare the earth, at what point in time would the earths orbit be affected. Would we notice the change before we observed it 8 minutes later.

In an infinite but static universe with an infinite number of stars olbers paradox says that every point in the sky would have a star in it. So everywhere would be bright and infact at the same temperature as the average stars temperature.

Q1) Would the infrequent arrival of photons from extraordinarily distant stars reduce the theoretical temperature / brightness of the sky?

Q2) If we accept the above and so the temperature of the sky is the average surface temp of all the stars then would the star surface temperature increase to infinity as well due to the effective heat loss from all of the stars being zero.

He felt he was fatiguing early during training and the last few metres of sprint competition. A blood test revealed a blood count of 149 and ferritin 23. I understand that the blood count is OK but not high, and the ferritin is very low. He is now on iron supplements and reports he is feeling better, but it could be placebo effect. Does low ferritin cause fatique and is his blood count high enough? He is a sprinter not an endurance athlete, but trainings can be quite aerobic at times.

We look after my dear Aunt who has Alzheimers or the like. She is in denial about the memory issues but is comfortable with us looking after her affairs because she has never been good with maths :)

Lately she is concerned about money of which she has none. Some years ago she did have some savings but that disappeared before we got involved. She donated the last of her savings to the church. Now on a weekly basis she spends all of her money until her card is declined, which prompts the same conversation. A lengthy explanation follows where every large item of expenditure has been forgotten, but she remains unconvinced and insists that someone (us) has spent her money while she was in hospital recently (4 years ago). Her memory is bad enough to have completely forgotten about her carpet getting flooded and a subsequent $2k bill for a new hot water cylinder installed 10 days earlier.

I am contemplating telling her that she never had any money (partly true) just to avoid the lengthy explanation, but don't feel good about doing that.

Does anyone else have any mechanisms they use to not get sucked into this cycle of explanation. It would be great to get some ideas or suggestions to try.

If 1 electron was removed from one object and placed on another object close by what would be the voltage difference between the objects?

A sprinter is often told not to run any sort of distance as it will destroy speed. A run of 10 - 20 mins would do wonders for the athletes aerobic capabilities and benefit the athlete by reducing recovery times. So how does it destroy speed. I can see why a speed session would be a real bad idea after an aerobic session, bit visa versa doesn't seem to pose any issues to my mind. Again some coaches say once you start going slower in a speed session go home. Destroys speed ... why?

If a team gets 4 tries and loses by less than 7 points do they pick up 2 bonus points?

Also can a team that draws get 2 for the draw and another bonus point if they score 4 tries?

Bernhard Kohl (3rd in Tour De France 2008) is quoted as saying "I was tested 200 times during my career, and 100 times I had drugs in my body,” he said. “I was caught, but 99 other times, I wasn’t. Riders think they can get away with doping because most of the time they do."

What do you know? Is this true?

There is too much in the way of numbers describing the amount of radiation leaking from the plant that no one knows whether it is equivalent to a truck load of bannanas or a 50 megaton thermonuclear bomb

I know it probably depends on engine size and body design, but in general what would be the best speed.

He was a German poet who smoked cigars and died in 1956 so probably knew little about the issues facing modern sport or health for that matter.

Many people close to the sport can tell if a performance is enhanced, not only by the performance but by the way it is achieved. So who do you think is the worst at "faking it"?

It was set in 1993. The current holder was subsequently pinged twice for drugs, although the first was cocaine six years after he set the record and his 2nd for steroids in 2001.

Surely everyone knows this was set using PED's. It has stood since 1990. It was broken 12 times in the 20 years prior to the current record, then nothing. The holder went on to be caught for steroids twice. The first time was 4 months after he set his record.

Given enough time will all of the worlds reactors eventually leak radiation. Or will they be decommissioned before this happens.

Everyone knows the time set was assisted by the wind and chemists. So why not reset it and start again.

For life to spring from non life something has to grow and reproduce itself. Are there any process's in the non living world where a substance synthesizes more examples of itself?

I work night shift occasionally and at times my mind drifts while driving. I don't feel like I am going to sleep but it does feel like I am not exactly aware of things around me for a second or so.