(Bellwether Media Jan. 1, 2016)
Pulleys are simple machines used to lift and move loads. Builders use pulley systems to lift tools or materials. Elevators use pulleys to move up and down. Kids will learn how pulleys make work easier and how they are often part of complex machines.
- Simple Machines: Blastoff Readers, Level 4
- 1626174768 / 9781626174764
- 0.8 oz.
- 6.1 x 0.2