Will get brainiest are bevs or hydrogen fuel cell vehicles a more promising transportation technology for the future? should car companies be required to produce electric cars?

Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies. molten iron has a density of 7.0g/cm cubed. in its solid state, iron has a density of 8.0g/cm cubed.

One object has a mass of 1 kg and another object has a mass of 3 kg. if the speeds are the same, which of the following is true about their kinetic energy?

The voltage applied across a given parallel-plate capacitor is doubled. how is the energy stored in the capacitor affected?