Investigating Pulleys - 4th class

4th Class investigated the use of pulleys. Our school caretaker made a wooden frame for our class to use as a test area. Each team of 3 used a 1kg bag of flour as a weight and measured the force required to lift using a single fixed pulley using a force meter. It was about 10 Newtons. They then used 2 pulleys, 1 fixed 1 movable to lift the same weight and measured the lift force required. It varied from about 3.5 to 5 Newtons for the teams. 

They then used their new knowledge of pulleys to make a 2 fixed-2 movable system suspended from a hook in the ceiling to assist our handyman in lifting loads up to the storage area in the roof. We attached a tray to it to allow him to load it with objects.