Odd Ball Interview Questions

[Zowghi]

which would tell you its size, not its weight, you're fired.

What, this would work. Everyone knows the density of an elephant off the top of their head

 

[Kingy]

“How many basketballs can you fit in this room?”

calculate the volume of the room by measuring the length, width and breadth. A basketball is 29.5 inches in circumference, which gives it a volume of about 435 cubic inches.

Suppose the room is 12' x 12' x 8'. That gives it a volume of 1,990,656 cubic inches. Now, if spheres filled a room with perfect efficiency (i.e. no air gaps between them), there would be 1,990,656/435 = 4756.22 i.e. 4756 basketballs in the room.

Now, spheres don't pack together perfectly efficiently. The most efficient packing arragement is where you have staggered layers. This has a density of Pi/(2*sqrt(3)). Multiplying this by our original amount gives us 4150 basketballs in a room 12' x 12' x 8'.

Can get a lot more than that in the room if the basketballs are deflated first.

Lol, that's brilliant!

Kudos to those who got the apples and oranges riddle, I missed that...

 

[Kingy]

For the elephant one I would throw it in a swimming pool and work out the displacement.

Similar to how you weigh boobs, only you can't weigh the swimming pool before and after...

 

[Deadbeat]

which would tell you its size, not its weight, you're fired.

Don't be ridiculous, it'd tell you the mass of the elephant. The volume of water displaced is not equal to the volume of whatever's doing the displacing, unless external force is used to fully submerge the object - it's a product of mass.

 

[Col_M]

Absolutely nothing.

The implication is that the water level would rise slightly due the volume of the brick, but the boat would now displace less water now that the brick is no longer on board, thus the effects cancel each other out, and there is no net effect to the water level.

Not quite

 

[Redman]

which would tell you its size, not its weight, you're fired.

And 1 litre of water is approximately 1 kg, therefore elephant weighed

 

[Jokester]

The elephant will displace it's own weight in water, assuming it floats. Start with a tank full to the brim, put elephant in and then take it out and measure the drop in water level, that plus surface area of the tank then tells you the volume and hence weight of water displaced.

Have I woken up yet?

 

[Abraham]

Don't be ridiculous, it'd tell you the mass of the elephant. The volume of water displaced is not equal to the volume of whatever's doing the displacing, unless external force is used to fully submerge the object - it's a product of mass.

No, so long as what you're putting in the water is denser than water, the water displaced will be the same volume as what you've put in. How could it possible be anything else?

And 1 litre of water is approximately 1 kg, therefore elephant weighed

No, water weighed, unless you know the density of an elephant it is useless.

What, this would work. Everyone knows the density of an elephant off the top of their head

 

[markweatherill]

A manhole cover is round because the manhole is round.

This also works for square ones.

The apples, oranges and basketball questions would benefit from being on a conveyor belt.

 

[Abraham]

The elephant will displace it's own weight in water, assuming it floats. Start with a tank full to the brim, put elephant in and then take it out and measure the drop in water level, that plus surface area of the tank then tells you the volume and hence weight of water displaced.

Have I woken up yet?

I don't think it would float, I get the impression elephants are pretty dense.

 

[Tefal]

No, so long as what you're putting in the water is denser than water, the water displaced will be the same volume as what you've put in. How could it possible be anything else?

elephants float though don't they?

 

[Morbius]

The elephant will displace it's own weight in water, assuming it floats. Start with a tank full to the brim, put elephant in and then take it out and measure the drop in water level, that plus surface area of the tank then tells you the volume and hence weight of water displaced.

Have I woken up yet?

The elephant will no doubt be measured as being slightly heavier than its actual weight, due to the extra air he inhaled before holding his breath.

 

[Deadbeat]

No, so long as what you're putting in the water is denser than water, the water displaced will be the same volume as what you've put in. How could it possible be anything else?

It's an obvious assumption that an elephant would float.

 

[Jokester]

If the elephant doesn't float it doesn't work as you can only then measure it's volume.

 

[Morba]

A manhole cover is round because the manhole is round.

WIN!

 

[Cosimo]

elephants float though don't they?

They float to keep their blue tennis shoes from getting wet.

 

[Kingy]

Not quite

A slightly pourous brick?

And 1 litre of water is approximately 1 kg, therefore elephant weighed

Wouldn't that give us the weight of water equal to the size of the elephant? Implying that everything weighs the same albeit multiplied by volume?

What determines weight? Density?

Forgive me, I'm ill, but more importantly, I found boobs greatly more interesting than physics during my short stint at school...

 

[Morba]

elephants float though don't they?

If i dont float then an elephant aint floating!

 

[Burnsy2023]

The elephant will displace it's own weight in water, assuming it floats. Start with a tank full to the brim, put elephant in and then take it out and measure the drop in water level, that plus surface area of the tank then tells you the volume and hence weight of water displaced.

Have I woken up yet?

Quite frankly, I'd be telling the interviewer that they need the right tool for the job and that's some industrial scales. There is no point reinventing the wheel and I'd say that the cost benefit analysis for not hiring scales would indicate that this current plan needs to be re-evaluated.

 

[Cosimo]

WIN!

Aye, he shows great potential. Hire him.