Which of these is not an example of a physical change?
a. a nail rusting
b. a rock cracking
c. blowing up a balloon
d. stretching a piece of clay

Ameter stick is pivoted at the 0.50-m line. a 3.0-kg object is hung from the 0.15-m line. where should a 5.0-kg object be hung to achieve equilibrium (the meter stick oriented horizontal and motionless)?

Much of the information taught in earth-space science would not be available if it weren’t for our remote sensing abilities. explain two ways our remote sensing strategies contribute to our knowledge of these topics.

Write down two additional questions about earth's magnetic field that will make your presentation more informative.