A figure skater begins spinning counterclockwise at an angular speed of 4.5 π rad/s. During a 4.8 s interval, she slowly pulls her arms inward and finally spins at 7.2 π rad/s.
What is her average angular acceleration
during this time interval?
Answer in units of rad/s
2
.

Step-by-step explanation:

Given that,

Initial angular speed of the skater,

Final angular speed of the skater,

Time interval, t = 4.8 s

We need to find her average angular acceleration  during this time interval. Let be the average acceleration of the skater. So,

So, her angular acceleration is .

x =±sqrt(1/3)

step-by-step explanation:

x+4/6x=1/x

multiply each side by 6x to get rid of the fractions

6x*(x+4/6x)=1/x*6x

distribute

6x^2 +4 = 6

subtract 4 from each side

6x^2 +4-4 = 6-4

6x^2 =2

divide by 6

6x^2/6 = 2/6

x^2 = 1/3

take the square root of each side

sqrt(x^2) = ±sqrt(1/3)

x =±sqrt(1/3)