January exam - good flash cards

What units do you measure force in?

Newtons

Define “friction”

A force that opposes motion

When two surfaces rub together, friction is caused. This friction causes:

Heat

How can friction be reduced?

By using lubricants, such as oil

What is the formula that links unbalanced force, mass and acceleration?

F = ma

How do ice particles move?

They don’t move, only vibrate

How do water particles move?

They move and slide around each other

How do steam particles move?

They move freely and quickly

What happens when a liquid boils to a gas?

The particles absorb heat energy and begin to vibrate faster, increasing the separation between them

Why does evaporation lead to cooling?

The water particles take away heat energy when the sweat turn from liquid to gas. Because of this, the original surface gets cooler.

How does a foil sheet reduce heat loss?

The foil sheet prevents the heat particles from escaping, since there’s a surface in top of them