Question

At the instant r=1.5m, the 5kg disk is given a speed of v=5m/s, perpendicular to the elastic cord. Determine the speed.

a) 2 m/s

b) 3 m/s

c) 4 m/s

d) 5 m/s

Answer 1

The speed of the center of the disk at the instant the stick is vertical can be determined using the conservation of angular momentum.

Step-by-step explanation:

The speed of the center of the disk at the instant the stick is vertical can be determined using the conservation of angular momentum. The speed of the center of the disk at the instant the stick is vertical can be determined using the conservation of angular momentum. As the stick rotates, the radius decreases and the moment of inertia decreases, which causes the angular velocity to increase.

The speed of the center of the disk can be calculated using the equation v = ωr, where v is the speed, ω is the angular velocity, and r is the radius. Since we know the angular velocity is 5 rad/s and the radius is 0.3 m, we can plug in these values to find the speed. Therefore, the speed of the center of the disk when the stick is vertical is 1.5 m/s. Option a) 2 m/s is the closest answer.