PHYS final (exam 4)

Calculate the tension in a horizontal string that whirls a 1.5 kg toy in a circle of radius 3.0m when it moves at 3.0m/s on an icy surface

F = 4.5

Where is the center of mass of a hollow soccer ball?

In the center of the ball

What formula do you use to determine how much faster?

vm/vb

If a trapeze artist rotates once each second while sailing through the air and contracts to reduce her rotational inertia to one-third of what it was, how many rotations per second will result?

w = 3.00 rotations per second

Consider 3 axes of rotation for a pencil; along the lead, at right angles to the lead at the middle, and at right angles to the lead at one end. Rate the rotational inertias about each axis from smallest to largest

Axis along the lead, through the center, through one end

Calculate the angular momentum of the person if the force of friction that keeps a 85-kg person sitting on the edge of a horizontal rotating platform when the person sits 2.0m from the center of the platform and has a tangential speed of 1.8 m/s

L = 310 kg*m^2/s

Where is the center of mass of a baseball? Where is its center of gravity?

The center of mass and the center of gravity are both at the center of the spherical ball

Inertia depends on mass; rotational inertia depends on mass and something else. What?

The distribution of mass about the axis of rotation

In a tapered cup, which end rolls faster?

The mouth

Calculate the torque produced by a 50-N force when a pipe extends the length of the wrench to 0.56 m

t = 28 N*m