Another maths quiz

[PaulB]

Sorry to do this, but the question was misleading by a factor of 1000. I'll try and show my working

<pedant mode>

61mm piston stroke,
122mm per revolution = 0.122m per revolution.

At 10,000 rpm that's 1220m per minute. (0.122 * 10000)

That's 73,200 m per hour (1220 * 60). Or 73.2 km per hour

I thought mach 59 sounded a little fast for piston speed 

</pedant mode>

Cheers

Paul B.

[Charlie747]

  My error   

The answer was miss leading by a factor of 1000 

We had better work on the number of times the piston stops and changes direction / sec when the crankshaft speed is 10000rpm

That happens twice per crankshaft revolution

So 10000rpm / 60 = revs per sec

= 166.667 revs per second

166.667 revs per second x 2 the number of times a piston stops and changes direction per revolution

= 333.334

Therefore a piston changes direction 333.34 times a second at and engine speed of 10000rpm

It makes you  think of the stress and load on an engine ? .............Well it does me 

Thanks for the correction PaulB 

PS hope I've got it right this time 

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