Help with rotation about a fixed axis

In summary, the first problem asks to find the angular speed of a record given its speed in revolutions per minute. The answer is 3.623 radians/second. The second part asks for the angle in radians that the record rotates in 0.717 seconds, which can be found using the formula distance = rate x time. In the second problem, a ball with a length of 1.8m is moving in a horizontal circle at a constant speed of 3.4 rev/s. The period, frequency, and angular velocity can be found using the known information and the formula for period. However, if the calculated values do not match the correct answers, it may be necessary to check for mistakes in the calculations.
  • #1
alexhavak
1
0
hey..i have a problem that states. a record has an angular speed of 34.6 rev/min. Find its Angular speed in rad/s.
-so the answer is 3.623.
The second part of the problem asks what angle, in radians, does it rotate in .717s. answers in rad.

do you think you can help me?

Also, i have some problems dealing with a ball at the end of the string with length 1.8m. It is in horizontal circle at constant speed. IT makes 3.4 rev/s. I need to find the period of the ball's motion, the frequency, and its angular velocity...but everything i have tryed has failed.
I tryed 1.848 and .18726 for the period but was wrong. i tryed 5.34 and .5411 for the frequency but was wrong and the velocity i also got wrong.

PLEASE HELP! I am new
 
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  • #2
alexhavak said:
i have a problem that states. a record has an angular speed of 34.6 rev/min. Find its Angular speed in rad/s.
-so the answer is 3.623.
The second part of the problem asks what angle, in radians, does it rotate in .717s. answers in rad.
What do you think the answer should be? If the angular speed is 3.623 radians/second, and the time is given as 0.717 seconds, how do you think you would get the angle in radians? (Hint: Angle is similar to distance, which equals rate X time.)


Also, i have some problems dealing with a ball at the end of the string with length 1.8m. It is in horizontal circle at constant speed. IT makes 3.4 rev/s. I need to find the period of the ball's motion, the frequency, and its angular velocity...but everything i have tryed has failed.
I tryed 1.848 and .18726 for the period but was wrong. i tryed 5.34 and .5411 for the frequency but was wrong and the velocity i also got wrong.
Don't just give your answers, show how you got those answers. (Then we can see where you made a mistake.) Here's a hint: I assume you know that period means the time for one revolution. If you know that 3.4 revolutions takes 1 second, how long will 1 revolution take?
 
  • #3
It has an angular velocity of 3.623 rad/sec. that means that,

in 1 sec it travels through an angle of 3.623 radians
so, in 0.717 secs it travels through an angle of ?

For the 2nd problem, convert your angular velocity from rev/s to rad/s :smile:
 

1. What is rotation about a fixed axis?

Rotation about a fixed axis is a type of circular motion in which an object or system is rotated around an axis that remains stationary. This is in contrast to rotation about a moving axis, in which the axis itself changes position during the rotation.

2. How is rotation about a fixed axis different from rotation about a moving axis?

Rotation about a fixed axis involves a stationary axis, while rotation about a moving axis involves an axis that changes position during the rotation. This can result in different types of motion and can have different effects on the object or system being rotated.

3. What are some examples of rotation about a fixed axis?

Some common examples of rotation about a fixed axis include the rotation of a bicycle wheel, the spinning of a top, and the motion of a merry-go-round. These all involve objects or systems rotating around a stationary axis.

4. How is rotational motion described and measured?

Rotational motion is typically described and measured using concepts such as angular velocity, angular acceleration, and moment of inertia. These quantities are used to calculate the rate and amount of rotation about a fixed axis.

5. What are the practical applications of understanding rotation about a fixed axis?

Understanding rotation about a fixed axis is important in many fields, including engineering, physics, and biomechanics. It can be used to analyze and design rotating machinery, study the motion of celestial bodies, and understand the movement of the human body during activities such as sports and dance.

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