When did man make fire?

When did man make fire?


Can you rub sticks together to make fire?

When two sticks are rubbed together, the action creates friction, which causes heat. Heat coaxes the wood into a smoldering charcoal, which is fed tinder and dry sticks to become a full-fledged fire. ... The sparks that result from striking the one stone against the other are hot and can be used for fire.

What happens when you rub two rocks together?

Rock Abrasion When two pieces of rock are rubbed together, the mineral grains in the rocks can be broken away from the rock surface. Rock abrasion occurs commonly in landslides where pieces of rock slide past one another as the mass moves downhill.

Why is spark produced when two stones are?

Q a spark is produced when two stones are struck against each other. Give reason. Answer the spark is produced because this collision is an inelastic collision and its mechanical energy is lost in form of light energy which appears as the spark. ... As work is done on two harsh bodies (rocks) so energy would be produced .

What happens when rocks are placed in water?

Erosion happens when rocks and sediments are picked up and moved to another place by ice, water, wind or gravity. Mechanical weathering physically breaks up rock. ... Water gets into cracks and joints in bedrock. When the water freezes it expands and the cracks are opened a little wider.

What does abrasion do to rocks?

Rocks break down into smaller pieces through weathering. Rocks and sediment grinding against each other wear away surfaces. This type of weathering is called abrasion, and it happens as wind and water rush over rocks. The rocks become smoother as rough and jagged edges break off.

What type of weathering is acid rain?

The weathering of rocks by chemicals is called chemical weathering . When acidic rainwater falls on limestone or chalk, a chemical reaction happens. ... New, soluble, substances are formed in the reaction.