What is the ratio of the sun’s gravitational pull on mercury to the sun’s gravitational pull on the earth?
a. the radius of the orbit of mercury is rm= 5.79× 1010m and its mass is mm= 3.30× 1023kg.
b. the radius of the orbit of earth is re=1.50× 1011m and its mass is me=5.97×1024kg.

Global warming will produce rising sea levels partly due to melting ice caps but also due to the expansion of water as average ocean temperatures rise. to get some idea of the size of this effect, calculate the change in length (in m) of a column of water 1.45 km high for a temperature increase of 1.12°c. assume the column is not free to expand sideways. as a model of the ocean, that is a reasonable approximation, as only parts of the ocean very close to

Describe how the motion of a spring being pushed forward and backward is similar to the motion of air particles in a sound wave.

Which of the following is a measure of the amount of light a star directly emits?               a.  luminosity    b.  intensity    c.  wavelength    d.  brightness