A disk of radius $25\mathrm{.}0cm$ is free to turn about an axle perpendicular to it through its center. It has very thin but strong string wrapped around its rim, and the string is attached to a ball that is pulled tangentially away from the rim of the disk $($Figure $1).$ The pull increases in magnitude and produces an acceleration of the ball that obeys the equation $a(t)=At,$ where $t$ is in seconds and $A$ is a constant. The cylinder starts from rest, and at the end of the third second, the ball's acceleration is $1\mathrm{.}70\frac{m}{s^2}.$

Part A

Find $A.$

Express your answer in meters per second cubed.

$A=$

$\frac{m}{s^3}$

Request Answer

Part B

Express the angular acceleration of the disk as a function of time.

Express your answer in radians per second cubed multiplied by $t.$

$(t)=$

$(ra\frac{d}{s^3})t$

Figure

$1$ of $1$

A disk of radius $25\mathrm{.}0cm$ is free to turn about an axle perpendicular to it through its center. It has very thin but strong string wrapped around its rim, and the string is attached to a ball that is pulled tangentially away from the rim of the disk $($Figure $1).$ The pull increases in magnitude and produces an acceleration of the ball that obeys the equation $a(t)=At,$ where $t$ is in seconds and $A$ is a constant. The cylinder starts from rest, and at the end of the third second, the ball's acceleration is $1\mathrm{.}70\frac{m}{s^2}.$

Figure

$1$ of $1$