Simplify the following text for a Grade 6 native English-speaking person.
Original: The forces required to do this are quite large : to remove a foot from quicksand at a speed of one centimeter per second would require the same amount of force as `` that needed to lift a medium-sized car . ''
Simplified: The forces required to do this are quite large : to remove a foot from quicksand at a speed of .01 m\/s would require the same amount of force as `` that needed to lift a medium-sized car . ''