Sir Isaac Newton was a 17th-18th century scientist and author who is thought to be one of the most important scientists in history.​

As per legend, he was inspired to make one of his most significant discoveries when he saw an apple falling out of a tree towards the ground.​

Which physical force that affects each and every one of us did Newton discover?​

The ability to create and use these is one major way in which humans are different from animals.​

These also allowed the first humans to become more efficient hunters and workers.​

Today, we use all kinds of ___ to help us carry out daily activities like brushing, eating, writing, and so on.​

Fill in the blank or tell me what I am describing here. 

Oars are tools or simple machines used to row small boats, canoes, and rafts. ​

In order to operate oars, muscular force needs to be applied to drag each one through water.​

Oars help to steer the boat and make it move much faster than otherwise possible. ​

Which type of simple machine system is the boat oar?

Road-going vehicles, regardless of how many wheels they have, have a braking system connected to the tires that allows them to stop or slow down.​

Brakes apply a type of force on moving objects causing them to heat up and slow down.​

Brakes convert the energy of movement into heat and for this reason they can sometimes get very hot.​

What type of force do brakes use to slow down moving object?

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Shown here is natural geysers shooting up water in Iceland.​

At a natural geyser, water seeps through cracks in the Earth’s crust, gets heated, and bursts upwards as steam. ​

​What energy, that is present deep inside the Earth, causes natural geysers to form?