When a book is resting on a level table and you are not pushing on it, is there a frictional force between the book and table?

What is the wavelength of an earthquake wave if it has a speed of 11 km/s and a frequency of 7 Hz?

9. A bullet is moving at a speed of 367 m/s when it embeds into a lump of moist clay. The bullet penetrates for a distance of 0.0621 m. Determine the acceleration of the bullet while moving into the clay. (Assume a uniform acceleration.)

Two 8 ohm resistor in parallel

Which of the following best describes reverberations

What is the best way to make a balloon racer.

A car slows down from 24 m/s to rest in a distance of 90 m. what was its acceleration, assumed constant? incorrect: your answer is incorrect. m/s2

Radar, the first link in the cosmic distance chain, is used to establish the baseline distance necessary for the second link, parallax. What baseline distance must we know before we can measure parallax?

What types of areas are more prone to floods?

would the phases of the moon be affected if the moon didn't make one rotation for each revolution of earth?

What kinetic energy has 1 tone car traveling at 15 m/s