If Earth is approximately 4.5 billion years old,estimate the order of magnitude for the number of times it has rotated about its own axis.(Assume a constant rate of rotation.)
Light travels at 3 108 m/s,and the size of a proton is about 1 fm.Calculate the order of magnitude for the time taken for light to pass across a proton.
If you have a music CD collection of about 150 discs,estimate the order of magnitude of the number of heartbeats you would have if you listened all the way through your collection.
A diehard music lover still prefers to listen to his vinyl records,which rotate at 33 revolutions per minute.If he listens for an average of three hours per day,estimate the order of magnitude for the number of revolutions his turntable makes in a year.