A wheel has a diameter of 250 ft and it rotates one complere revolution every 20 minutes. find the linear speed in m/h
If u think u got th right answer, show how?
2006-07-25 17:18:12 · 13 answers · asked by boygenis 3 in Science & Mathematics ➔ Mathematics
The circumference is pi*250.0 = 785.4 feet = 0.1487 miles
one rev every 20 min = one rev in 1/3 hour.
speed = 0.1487miles/0.3333 hour = 0.4462 miles/hour
2006-07-25 17:25:00 · answer #1 · answered by Will 6 · 5⤊ 0⤋
250 times 3 = 750 so the wheel covers a distance of 750 feet in an hour. Since there are 5260 feet in a mile then you must divide 750 by 5260 which is 0.1425 so the wheel is traveling at 0.1425mph. Got that!
2006-07-25 17:31:10 · answer #2 · answered by truman 1 · 0⤊ 0⤋
firstly you need to know that when a wheel rotates it is travelling on its circumference.
so you need to find your circumference of the wheel:
pi x diameter = 3.14 x 250 = 785 feet
this would mean that this wheel takes 20 minutes (1/3 h) to travel the whole length of its circumference 785 feet ( 1 ft = 0.3048m. 785 ft = 239.3m)
now to find speed, this would mean taking distance / time
= 239.3m / (1/3)h
= 717.9m/h
not to difficult is it?
2006-07-25 17:28:50 · answer #3 · answered by Anonymous · 0⤊ 0⤋
well in one full rotation it'd do the circumference's revolution, meaning 250*pi. In one hour it'd 60/20 times this, so 750*pi. divide it by the amount of feet in a mile (I'm Canadian, so I have to look that up) which is 5280, and you get:
0.44624895647582290319071638967038 miles/hour, or using 3.14 for pi instead of the longass number:
0.44602272727272727272727272727273
2006-07-25 17:30:50 · answer #4 · answered by herman_gill 2 · 0⤊ 0⤋
1 revolution every 20 minutes equals 3 revolutions in 1 hour.
1 revolution equals circumference of tire.
Circumference equals Pi times diameter.
Use 3.14159 for Pi.
Diameter is 250 feet...given.
Circumference is 3.14159 times 250 feet.
Circumference equals 785.3975 feet.
1 revolution equals 785.3975 feet.
3 revolutions equals 3 times 785.3975 feet.
3 revolutions equals 2,356.1925 feet
Distance traveled in 1 hour equals 2,356.1925 feet
1 mile equals 5,280 feet.
Miles traveled in 1 hour equals 2,356.1925 divided by 5,280.
Miles traveled in 1 hour equals .4462 miles in one hour which is the same thing as .4462 miles per hour.
2006-07-25 18:24:45 · answer #5 · answered by Intelligent and curious 3 · 0⤊ 0⤋
That's one big wheel! Ok, it will turn three times per hour. It's circumference is pi D, or about 800 ft (this is all estimation, I don't feel like getting my calculator). So it will go 2400 ft per hour, so it's about 1/2 mile per hour.
2006-07-25 17:24:30 · answer #6 · answered by Master Maverick 6 · 0⤊ 0⤋
2*PI*r -> 2*3.14*125 = 785 ft = 785*0.000189393939 miles = 0.148 miles -> distance travelled
20 min = 20/60 = 1/3 hr -> time
Speed = distance/time = 0.148*3 = 0.44 miles/hr
2006-07-25 17:27:44 · answer #7 · answered by AM 1 · 0⤊ 0⤋
its like 1/2mile per hour. 250ft time pi is the circumference...785ft. the wheel goes 785 feet three times during an hour..thus 2355 feet per hour...which is like 1/2 mile.
2006-07-25 17:26:14 · answer #8 · answered by queStionmarK 2 · 0⤊ 0⤋
K- so I did have my formula wrong... Try again!
C = pi(diameter)
C = 3.14(250)
C = 785
1 rev/20 min = 3 rev/hour....
(785 x 3)/hour = 2355 feet/ hour
0.446 022 727 mile/hour....
2006-07-25 17:36:55 · answer #9 · answered by Yoda's Duck 6 · 0⤊ 0⤋
0.45 miles an hour, just a guess, I worked this in my head in like 1 minute.
2006-07-25 17:25:06 · answer #10 · answered by Ben D 2 · 0⤊ 0⤋