What formula is used to calculate density

A construction worker puts 20J of energy in to one strike of his hammer on the head of a nail. The energy transferred to driving d nail in to d wood is 8J. What is d efficiency of d construction worker's hammering?

I need to make a box that would keep foods hot, but can only use 1 out of the following 4 materials; rubber, glass, aluminum foil, and stainless steel. Which material would be best to use to make the box?

Describing motion verbally with distance and displacement

Which is more dense, a clear plastic block or a glass block?

What is electromagnetic waves

The instantaneous velocity of an object is the blank of the object with a blank

Which of the following best describes the earth's average surface temperature for the past 900,000 years? A. a steady warming trend B. fairly steady temperatures until recently C. prolonged periods of cooling and warming D.

What should you always include in a great summary? (Select all that apply) A. investigation plan B. possible errors C. predictions D. new questions

What are the "base units" in the S. I. system?

What action happens if the moon spins on its axis like a top