Which is a characteristic of a physical change?

the chemical bonds in the substance are unchanged.
the change cannot be seen.
the molecules all move at the same speed.
the substance has reacted with another substance.

To travel at constant speed, a car engine provides 24kw of useful power. the driving force on the car is 600n. at what speed does it travel?

Which of these activities increases the amount of carbon in the atmosphere?

Which of the following statements are true for an isothermal process? check all that apply. - during an isothermal process, the work done by the gas equals the heat added to the gas. - during an isothermal process, the internal energy of the system changes. - an isothermal process is carried out at constant temperature. - an isothermal process is carried out at constant pressure. - an isothermal process is carried out at constant volume.