Your spacecraft lands on an unknown planet. To determine the characteristics of this planet, you drop a 1.3 kg wrench from 5 m above the surface and find that it hits the ground 0.811 s later.
You know that the circumference of the planet is 62,400 km. What is the planet's mass?

Astudent is given an assignment to demonstrate diffraction. he takes a photograph of a straw in a glass of water. the straw appears bent at the water level. which best describes this example? a) this is a good example of diffraction. b) this is an example of dispersion and not diffraction. c) this is an example of refraction and not diffraction. d) this is an example of reflection and not diffraction.

Zeros that follow non-zeros numbers and are also to the right of a decimal point are significant

Which explanation describes the forces involved for a person to walk down the sidewalk? a. the person's feet push backward on the sidewalk; the sidewalk pushes backward on the person. b. the person's feet push forward on the sidewalk; the sidewalk does not push on the person. c. the person's feet push backward on the sidewalk; the sidewalk pushes forward on the person. d. the person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.