Which one of the following is not a balanced equation?
a. 2ca (s) + o2 (g) → 2cao (s)
b. ca (s) + o2 (g) → cao (s)
c. 2li (s) + 2h2o (l) → 2lih (aq) + h2 (g)
d. ch4 (g) + 2o2 (g) → co2 (g) + 2h2o (g)

James is trying to prove newton's 2nd law of motion. he tries to move four different objects with different masses, shapes, and sizes from point a to point b. the objects are a toy car, a car, a refrigerator, and a kitchen table. after some experimentation, he finds that force is dependent on the mass of the object, rather than it's size or shape. the object that takes the most force to move is the

If a simple machine reduces the strength of a force, what must be increased?

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?