An object dropped from rest almost infinitely far from earth falls to earth because of earth's gravitational field, and strikes the surface with a speed of about
a. 8 km/s
b. 9.8 m/s
c. 11 km/s
d. none of the above

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.

Which statement is true? a. kepler's laws apply only to the motion of earth. b. kepler's laws can be used to predict eclipses. c. kepler's laws are true for a central force that is directly proportional to distance. d. kepler's laws can be deduced from newton's laws of motion and gravity.

How to calculate voltage drop in a series circuit