Question

Give reason why?

1. The early man could produce fire by rubbing together two stones.
2. Aeroplanes can move at much greater speed than motor cars.
do to run in brass sockets or bearings


please give the ans​

Answer 1

1. The early humans discovered fire by rubbing two flint stones against each other. They used to make fires in front of the caves to scare away wild animals. ... Tools made from flint stones and animal bones were used for various purposes. They also used to paint on cave walls for their recreation.

2. planes do not have any contact with road so it has less friction and planes have much powerful engines as compare to cars. Thus, aeroplanes can move at a greater speed than motorcars related to friction.

I hope it help you...

Answer 2

Answer:

1. The above mentioned activity was done by early humans. the early humans discovered Fire by rubbing two flint stones against each other . They used to make fires in front of caves to scare away wild animals .

2. Planes do not have any contact with roads so it has less friction and planes have much powerful engines as compared to cars .

Thus , aeroplanes can move at much greater speed than motor cars related to friction.