O'Reilly logo

Head First Physics by Heather Lang

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Chapter 13. Torque and Work: Getting a lift

image with no caption

You can use your physics knowledge to do superhuman feats. In this chapter, you’ll learn how to harness torque to perform amazing displays of strength, by using a lever to exert a much larger force than you could on your own. However, you can’t get something for nothing - energy is always conserved and the amount of work you do to give something gravitational potential energy by lifting it doesn’t change.

Half the kingdom to anyone who can lift the sword in the stone ...

The sword in the stone has acquired near-legendary status. But now, in a shock move, anyone can attempt to lift it.

There are rules of course - but the promise of half the kingdom for anyone who succeeds is completely genuine.

image with no caption

Can physics help you to lift a heavy object?

The rules say that the crossguard of the sword must go up by at least 10.0 cm to reach the line. But they don’t say anything about whether the sword needs to be detached from the stone at the time!

image with no caption

If you can use physics to lift both the sword and the stone 10.0 cm off the ground, you’ll win. The only thing is the stone is far too heavy for one person to lift on their own, and it’s not like you can take it to the ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required