If Seismic waves that go straight thorough Earth make the trip very quickly. What does that tells us about the composition of Earth's center?

What is created when solids, liquids, an gases mix with one another

In the circuit shown below, with each bulb holding a resistance of 60 ohms, how many amps of current are flowing? express your number as a decimal.

Two conductors, a and b, are each in the shape of a tetrahedron. but of different sizes. they are charged in the following manner: 1. tetrahedron a is charged from an electrostatic generator to charge q. 2. tetrahedron a is briefly touched to tetrahedron b. 3. steps 1 and 2 are repeated until the charge on tetrahedron b reaches a maximum value. if the charge on tetrahedron b was q/4 after the first time it touched tetrahedron a. what is the final charge qbmax on tetrahedron b?