A uniform disk of radius 0.2 m and mass m = 16 kg is mounted on a nearly frictionless axle. A string is wrapped tightly around the disk and pulled with a constant force of F = 1 N. After a while the disk has reached an angular speed of !0 = 1.2 rad/s. What is its angular speed 1.5 s later?

ω = 2.13rad/s

Explanation:

Given

F = 1N = force applied, m = 16kg, R = 0.2m

ωo = 1.2rad/s

t = 1.5s

ω = ?

Where

α = angular acceleration

ωo = initial angular speed

And ω = angular speed at a later time t

For a rigid body rotating about an axis

τ = FR= I×α

I = 1/2×MR² for a uniform disk

FR = (1/2×mR²)×α

= 1/2×mR²×(ω – ωo)/t

Therefore

FR= 1/2×mR²×(ω – ωo)/t

2Ft/mR = ω – ωo

ω = 2Ft/mR + ωo

ω = 2×1×1.5/(16×0.2) + 1.2 = 2.13 rad/s

depends on what you mean by "group." for order, it would be coleoptera (beetles). for class, it would be insecta (insects). for phylum, it would be the arthropoda (animals with jointed exoskeletons).

explanation: