M
millionaremind007
Guest
1. Find the radian measure of the central angle of a circle of radius r that intercepts an arc of length s.
r = 1 meter, s = 300 centimeters
From what I did in the past THETA = S/R where in this case would equal 300/1 = 300 radians however I got it wrong, not sure what I'm missing.
2. A pick-up truck is fitted with new tires which have a diameter of 43 inches. How fast will the pick-up truck be moving when the wheels are rotating at 360 revolutions per minute? Express the answer in miles per hour rounded to the nearest whole number.
I had a lot of trouble with this. This is what I did. Diameter is 43 so 43/2 gives you a radius of 21.5 inches.
360 rev * 2Pi = 720 PI = omega
1 minute 1 Rev 1 rev/m
v = r(omega)
v = (21.5 inches) (720 PI ) = 15480 PI
1 rev/m 1 rev/m
v= 15480 PI inches * 1 hour = 258 PI inches
1 rev/m 60 m 1 rev/hr
Then I have no clue what to do or if I did this right, help!
3. To approximate the speed of a river, a circular paddle wheel with radius 0.55 feet is lowered into the water. If the current causes the wheel to rotate at a speed of 13 revolutions per minute, what is the speed of the current? Express the answer in miles per hour rounded to two decimal places, if necessary.
I could of sworn I got this question right. V = R(OMEGA)
R= .55 ft
13 revs * 2pi = 26pi * .55 = 14.3PI feet = 44.92 ft
1 M 1 rev 1 rev/m 1 rev/m 1 rev/m
Yet I still got this incorrect. What did I do wrong?
r = 1 meter, s = 300 centimeters
From what I did in the past THETA = S/R where in this case would equal 300/1 = 300 radians however I got it wrong, not sure what I'm missing.
2. A pick-up truck is fitted with new tires which have a diameter of 43 inches. How fast will the pick-up truck be moving when the wheels are rotating at 360 revolutions per minute? Express the answer in miles per hour rounded to the nearest whole number.
I had a lot of trouble with this. This is what I did. Diameter is 43 so 43/2 gives you a radius of 21.5 inches.
360 rev * 2Pi = 720 PI = omega
1 minute 1 Rev 1 rev/m
v = r(omega)
v = (21.5 inches) (720 PI ) = 15480 PI
1 rev/m 1 rev/m
v= 15480 PI inches * 1 hour = 258 PI inches
1 rev/m 60 m 1 rev/hr
Then I have no clue what to do or if I did this right, help!
3. To approximate the speed of a river, a circular paddle wheel with radius 0.55 feet is lowered into the water. If the current causes the wheel to rotate at a speed of 13 revolutions per minute, what is the speed of the current? Express the answer in miles per hour rounded to two decimal places, if necessary.
I could of sworn I got this question right. V = R(OMEGA)
R= .55 ft
13 revs * 2pi = 26pi * .55 = 14.3PI feet = 44.92 ft
1 M 1 rev 1 rev/m 1 rev/m 1 rev/m
Yet I still got this incorrect. What did I do wrong?