Back-of-the-Envelope Calculations: Weight of Gold part of Quantitative Skills:Activity Collection
Barb Tewksbury, Hamilton College
Question Let's suppose that you have a shoe box full of water (the box is waterproof, of course). The shoe box weighs about 9 kg (19.8 pounds). Suppose you emptied the box and filled it completely with rock ...

Back-of-the-Envelope Calculations: The Distance Radio Waves Have Traveled part of Quantitative Skills:Activity Collection
Barb Tewksbury, Hamilton College
Question We have been broadcasting radio waves in all directions since the development of radio and television stations. How far could you be from the Earth and detect the faint signals of an early Star Trek ...

Back-of-the-Envelope Calculations: Communication with Mars part of Quantitative Skills:Activity Collection
Barb Tewksbury, Hamilton College
Question Suppose you were living in a Mars colony, and you wanted to call home to your parents on Earth. You say, "Hello! How are you?" How long do you have to wait until you hear them say, ...