Which category of materials allows electrons to travel through them freely

Although light from the sun appears white, it is actually made up of a lot of different colors. this portion of the electromagnetic spectrum, we call white light is referred to as within the electromagnetic spectrum.

Adiver in midair has an angular velocity of 6.0 rad/s and a moment of inertia of 1.2 kg·m2. he then pulls is arms and legs into a tuck position and his angular velocity increases to 12 rad/s. the net external torque acting on the diver is zero. what is his moment of inertia in the tuck position?

How are calculation for velocity and speed different