Any one hav an answer to this question?

Question

.. for a four stroke otto cycle engine running at 3000 rpm , how many times per second does the inlet valve open?

Answer 1

the answer is 12.5 easy

Answer 2

12.5 times

Answer 3

12.5

Answer 4

Lets split the difference! 100/12.5 = 8 + 25 = 33. thanks Bob, Blob and Slob for your answers!!!!!

Answer 5

how big is the engine?

Answer 6

25 times per second per cylinder.

Answer 7

100

Answer 8

12.5 assuming that we are talking about a single cylinder engine.

Edit

25 is the correct answer sometimes I type faster than I think here is how to calculate.

The intake valve opens every 2nd revolution (or 4 strokes) think of it like this intake valve opens (revolution one); compression stroke with no valve open (rev 1); combustion stroke no valves open(rev 2); exhaust stroke exhaust valve open (rev 2); the formula would be

(rpm)/(seconds)/2(revolutions) =      

3000/60=50(revolutions per second)=

50/2= 25

Answer 9

That's 50 revs per second, and the valve will open for every two revolutions of the crankshaft, so it would be 25.

An engine RPM is one revolution of the crankshaft, not one complete 4 stroke cycle, which takes two revolutions. That is why the answer is 25.