3 Change the incorrect word in each sentence. pulley
a. A lever uses rope and a wheel to lift and lower heavy objects. b. A screw can be used to cut objects. c. A pulley can be used to move objects from one place to another. d. An wedge is used to move objects up and down different levels. e. A inclined plane uses a rigid bar and a fulcrum to lift objects. f. A wheel and axle is used to hold things together.
4 Identify the simple machines in each picture.
a
wedge
screw
pulley
wheel and axle
lever
a d c b e
5 Look at the photos. Do they show inventions from the industrial revolution or the communication revolution? a
b
c
6 Read the descriptions and write the invention. a. This invention sent tapped messages. b. This vehicle could travel about 40 kilometres in one hour. c. This was invented about 140 years ago and still helps people communicate today. d. This vehicle uses batteries and is better for the environment than a normal car.
