Which of the following would you describe as a change in state?
a) melting ice
b) burning paper
c) film being exposed to light
d) a piece of paper being cut in half

If gases like carbon dioxide and methane make up less than 1% of the total atmosphere, why is it important for scientists to monitor changes in percentages of these gases?

Aforklift raises a 1,020 n crate 3.50 m up to a shelf. how much work is done by the forklift on the crate? the forklift does j of work on the crate.

Simon is writing a story about an astronaut whose spacecraft has been boarded by space pirates. the astronaut has her lucky penny in her hand behind her back as the space pirates break into the control room. she has just locked the controls so that the ship is accelerating in the direction of the control room’s ceiling. simon wants the astronaut to use the penny to hit a button on the control panel to turn off the lights and escape. the button is located a short distance behind and below the astronaut’s hands. how should simon use the theory of relativity to describe what the astronaut must do in order to hit the button?