Work = (weight) x (distance lifted)
= (100 N) x (0.5 m)
= 50 joules.
If you carry the sled level all the way to your house, you're not moving it
against gravity.
Although you're huffing and puffing and sweating by the time you reach
your house, still, according to the Physics definition of work, you have
done NO work on the sled all the way home.
