Question

In: Physics

A cooling fan is turned off when it is running at 840 rev/min . It turns...

A cooling fan is turned off when it is running at 840 rev/min . It turns 1400 revolutions before it comes to a stop. Part A:What was the fan's angular acceleration, assumed constant? Part B: How long did it take the fan to come to a complete stop? Please show step by step

Solutions

Expert Solution

Initial rotational speed of the cooling fan = N1 = 840 rev/min

Initial angular speed of the cooling fan = 1

1 = 87.96 rad/s

Final angular speed of the cooling fan = 2 = 0 rad/s

Number of revolutions made by the cooling fan = n = 1400 rev

Angle through which the fan has rotated =

= 2n

= 2(1400)

= 8796.46 rad

Angular acceleration of the fan =

22 = 12 + 2

(0)2 = (87.96)2 + 2(8796.46)

= -0.44 rad/s2

Negative as the fan is slowing down.

Time taken by the fan to come to a stop = T

2 = 1 + T

0 = 87.96 + (-0.44)T

T = 200 sec

A) Angular acceleration of the fan = -0.44 rad/s2

B) Time taken by the fan to come to a stop = 200 sec


Related Solutions

A cooling fan is turned off when it is running at 840 rev/min . It turns...
A cooling fan is turned off when it is running at 840 rev/min . It turns 500 revolutions before it comes to a stop. 1.) What was the fan's angular acceleration, assumed constant? 2.) How long did it take the fan to come to a complete stop?
A cooling fan is turned off when it is running at 900rev/min . It turns 1100...
A cooling fan is turned off when it is running at 900rev/min . It turns 1100 revolutions before it comes to a stop. Part B How long did it take the fan to come to a complete stop?
An electric fan is turned off, and its angular velocity decreases uniformly from 460 rev/min to...
An electric fan is turned off, and its angular velocity decreases uniformly from 460 rev/min to 210 rev/min in a time interval of length 4.15 s . a)Find the angular acceleration in rev/s2. b)Find the number of revolutions made by the motor in the time interval of length 4.15 s . c)How many more seconds are required for the fan to come to rest if the angular acceleration remains constant at the value calculated in part A? An airplane propeller...
. Ten seconds after an electric fan is turned on, the fan rotates at 300 rev/min....
. Ten seconds after an electric fan is turned on, the fan rotates at 300 rev/min. Its average angular acceleration is: a. 3.14 rad/s2 b. 30 rad/s2 c. 30 rev/s2 d. 50 rev/min2
A ceiling fan is turned on and reaches an angular speed of 120 rev/min in 50...
A ceiling fan is turned on and reaches an angular speed of 120 rev/min in 50 sec. It is then turned off and coasts to a stop in 40 s. Find the total number of revolution made before the fan stops
An electric motor is turned off, and its angular velocity decreases uniformly from 900 rev/min to...
An electric motor is turned off, and its angular velocity decreases uniformly from 900 rev/min to 400 rev/min in 6.00 s. (a) Find the angular acceleration and the number of revolutions made by the motor in the 6.00-s interval. (b) How many more seconds are required for the motor to come to rest if the angular acceleration remains constant at the value calculated in part (a)?
A 5 kW split-phase motor running at 1750 rev/min is used to drive a rotary pump,...
A 5 kW split-phase motor running at 1750 rev/min is used to drive a rotary pump, which operates 24 hours per day. An engineer has specified a 200 mm small sheave, and 300 mm large sheave, and B3000 belts. The service factor was 1.3. Analyze the drive and estimate: (a) center-to-center distance. (b) suitable number of belts. (c) F1, F2, Fc and Fi. (d) the factor of safety. (e) the belt life in passes
The flywheel of a steam engine runs with a constant angular velocity of 180 rev/min. When...
The flywheel of a steam engine runs with a constant angular velocity of 180 rev/min. When steam is shut off, the friction of the bearings and of the air stops the wheel in 1.1 h. (a) What is the constant angular acceleration, in revolutions per minute-squared, of the wheel during the slowdown? (b) How many revolutions does the wheel make before stopping? (c) At the instant the flywheel is turning at 90.0 rev/min, what is the tangential component of the...
The flywheel of a steam engine runs with a constant angular velocity of 140 rev/min. When...
The flywheel of a steam engine runs with a constant angular velocity of 140 rev/min. When steam is shut off, the friction of the bearings and of the air stops the wheel in 2.6 h. (a) What is the constant angular acceleration, in revolutions per minute-squared, of the wheel during the slowdown? (b) How many revolutions does the wheel make before stopping? (c) At the instant the flywheel is turning at 70.0 rev/min, what is the tangential component of the...
EMg is not a good tool for measuring? -when a muscle turns on and off -the...
EMg is not a good tool for measuring? -when a muscle turns on and off -the amount if load lifted in pounds -the number of active motor units -muscle fatigue
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT