The bottom layer of the crust is heavier rock like

Which of the following is not am example of a polymer? protein nylon kevlar concreta

How much energy is supplied to each coulomb of charge that flows through a 12-v battery?

Ahot-air balloon takes off from the ground traveling vertically with a constant upward acceleration of magnitude g/4. after time interval δt, a crew member releases a ballast sandbag from the basket attached to the balloon. how many seconds does it take the sandbag to reach the ground? (express your answer in terms of δt)