Two people climbed to the roof of a building. The old person walked up a gentle ramp. The young person climbed up a steep spiral staircase. If they weigh the same, which person did more work? Explain.

Which best describes how fluids change as they travel through different portions of the convection currents? they change to solids at the outer portion of the convection currents. they change to solids at the inner portion of the convection currents. they become more dense at the outer portion of the convection currents. they become more dense at the inner portion of the convection currents