According to the Big Bang theory, after the "Bang", the universe remained dark until about ___ later, when neutral atoms began form.

*three minutes

*one billion years

*300,000 years

*three billion years

Solve for real t: - 25=20t-5t^2

How do patterns in motion of the stars tell us about the origin of our Universe?

Two people are pushing a couch from opposite sides. one person pushes with a force of 2 N. the other person pushes with a force of 4 N. which of the following best describes how the couch will move?

Modeled after the two satellites problem (slide 12 in Lecture13, Universal gravity), imagine now if the period of the satellite is exact 88.59 hours, the earth mass is 5.98 x 1024 kg, and the radius of the earth is 3958.

The linear density of a string is 1.9 * 10-4 kg/m. A transverse wave on the string is described by the equation y = (0.034 m) sin[ (2.8 m-1) x + (38 s-1) t] What are (a) the wave speed and (b) the tension in the string?

As an astronaut travels towards Earth, her weight A. decreases because gravity decreases. B. decreases because her mass decreases. C. increases because gravity increases. D. remains the same because her mass remains the same.

Lightning often strikes water. a. True b. False

How much work must be done on a 10 kg snowboard to increase its speed from 4 m/s to 6 m/s?

If a spacecraft that seems to be motionless in deep space is given some type of quick push, what will happen? A. The spacecraft will not move because it only works on earth. B.

A fast, white water cascade is also known as what?