Last week, we learned about forces. We discovered that humans have used simple machines such as wheels, levers and pulleys for many years to help increase the pushing or pulling force they can exert. We read about engineers who design machines to do jobs that humans can't do on their own. We learned that forces are measured in Newtons (after the famous scientist Isaac Newton) and the amount of Newtons needed to move something can be measured using a force meter.
We also learned about friction. Friction is an invisible force that slows down a moving object. The smoother the surface, the less friction we experience. This is why cars slip on icy roads and special trucks have to grit the surface to increase friction. We talked about situations we might want to increase and decrease friction... Some examples we came up with were oiling a bicycle chain to reduce friction, putting water on a bouncy castle slide in the summer to reduce friction and help us go down faster, ridged tyres on 4x4s and trucks to increase friction.
Then, we conducted an experiment using a toy car and a ramp. We tested how far a car would travel having come down from a ramp on different surfaces: carpet, lino, the hallway, tarmac and grass. We also had to use maths as we measured the distance travelled in cm using a metre stick. Finally, we discovered that the grass had most friction (with cars travelling an average of only 4cm) while the smooth surface of the hallway had very little friction and most cars travelled more than 1m.
We also learned about friction. Friction is an invisible force that slows down a moving object. The smoother the surface, the less friction we experience. This is why cars slip on icy roads and special trucks have to grit the surface to increase friction. We talked about situations we might want to increase and decrease friction... Some examples we came up with were oiling a bicycle chain to reduce friction, putting water on a bouncy castle slide in the summer to reduce friction and help us go down faster, ridged tyres on 4x4s and trucks to increase friction.
Then, we conducted an experiment using a toy car and a ramp. We tested how far a car would travel having come down from a ramp on different surfaces: carpet, lino, the hallway, tarmac and grass. We also had to use maths as we measured the distance travelled in cm using a metre stick. Finally, we discovered that the grass had most friction (with cars travelling an average of only 4cm) while the smooth surface of the hallway had very little friction and most cars travelled more than 1m.