what machine can be used to ram piles into the ground?
a man, weighted down with ballast, climbs up a ladder. at the top, he places his feet in stirrups that are connected to a rope that runs over a winch and is anchored to a pile-driver. the pile-driver lying on the ground is raised upward when the man jumps downward. once on the ground, the man climbs out of the stirrups and the pile-driver rushes down and strikes a pile planted in the ground. this procedure can be repeated at will. the force of the impact can be increased by using a heavier pile-driver and correspondingly more men in the procedure.
- why does something move?
- how can flowing water consume its momentum when it encounters an obstruction?
- why are the waves of descending rivers slower than the water flow of the river itself?
- why does a body move when something strikes it?
- under what conditions can a person on a see-saw not jump up?
- why does waves look like crescents when viewed from the side?
- what happens to the waves when water crashed into an obstacle?
- what effects do the slope of the obstruction and the angle of impact have?
- why doesn't viscous water flow continually throungh a bent pipe?
- does the weight of water vary according to how one changes the slope of a pipe filled with water?
- how can one see that movement separates from its cause?
- where does the wave break?
- what causes cyclones?
- can a special dam influence the impact of the water?
- what must an especially strong dam look like?
- how can one simulate the collapse of a wave?
- how does air, once it is immersed, escape the water?