Question

if the direction of angular velocity is changing and magnitude is constant, is there any tangential acceleration component?​

Answer 1

Answer:

Angular velocity is not constant when a skater pulls in her arms, when a child starts up a merry-go-round from rest, or when a computer’s hard disk slows to a halt when switched off. In all these cases, there is an angular acceleration, in which ω changes. The faster the change occurs, the greater the angular acceleration. Angular acceleration α is defined as the rate of change of angular velocity. In equation form, angular acceleration is expressed as follows:

α=ΔωΔt" role="presentation" style="font-family: proxima-nova, sans-serif; -webkit-font-smoothing: subpixel-antialiased; padding: 1px 0px; margin: 0px; font-size: 17.44px; vertical-align: baseline; background: transparent; border: 0px; outline: 0px; display: table-cell !important; line-height: 0; text-indent: 0px; text-align: center; text-transform: none; font-style: normal; font-weight: normal; letter-spacing: normal; overflow-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 3.384em; min-height: 0px; width: 10000em; position: relative;">α=ΔωΔtα=ΔωΔt,

where Δω is the change in angular velocity and Δt is the change in time. The units of angular acceleration are (rad/s)/s, or rad/s2. If ω increases, then α is positive. If ω decreases, then α is negative.