Why do astronauts weigh less on the moon than they do on Earth? A. The moon has less mass than Earth.
B. Earth has less mass than the moon.
C. The mass of the Earth and moon are equal.

Name three different units of energy used to measure heat and describe what type of situations each is usually used.

1. how to locate the image in converging(concave) mirror and diverging (convex) mirror with salt. 2. how to locate the image in a converging (convex) lens and diverging (concave) lens with salt.

The mass of the sun is 1.99×1030kg and its distance to the earth is 1.50×1011m. what is the gravitational force of the sun on the earth?