diameter pulley is running at 1,548 revolutions per minute. If the speeds of the pulleys vary inversely to their diameters, how many revolutions per minute does the larger pulley make?
2007-05-29 13:38:38 · 6 answers · asked by Greg L 3 in Science & Mathematics ➔ Mathematics
Hi,
1032 because
8............x
-----..=..------- (revolutions are switched - inversely related)
12........1548
Cross-multiply and solve!!
I hope that helps!! :-)
2007-05-29 13:46:27 · answer #1 · answered by Pi R Squared 7 · 0⤊ 0⤋
Take into account the surface speed of the pulleys, because that is what the belt is riding on.
Circumference of 8" pulley = 8 pi
Surface speed = 1,548 rpm/8 pi
This reduces to inches per minute which has to be equal to the surface speed of the 12" pulley assuming no friction and no slippage. The magic of your problem is that 8" = 2/3 of a foot and pi is constant so it cancels out and the rotational speed (rpm) of the 12 " pulley is 2/3 the speed of the 8" pulley so 1548*2/3 and I'll let you do the arithmetic and come up with 1032.
2007-05-29 13:58:09 · answer #2 · answered by Anonymous · 0⤊ 0⤋
8 Inch Pulley
2016-10-22 02:08:58 · answer #3 · answered by ? 4 · 0⤊ 0⤋
8/12 x 1548
= 2 / 3 x 1548
= 2 x 516
= 1032
Larger pulley makes 1032 revs / min
2007-05-29 23:06:20 · answer #4 · answered by Como 7 · 0⤊ 0⤋
If the diameters can be used as given, then 1032 rpm.
In the real world, you have to use the pitch diameter which is less than the measured outside diameter.
2007-05-29 13:44:10 · answer #5 · answered by Mike1942f 7 · 0⤊ 0⤋
um dunno
2007-05-29 13:42:13 · answer #6 · answered by Queen 4 · 0⤊ 2⤋