Does the coefficient of kinetic friction depend on speed?

Which of the following explains why it took so long for the public to accept the negative health effects of smoking? a)people were waiting for counter reasons, and those were presented. b)scientists had not completely finalized their results, which took 30 years. c)cigarettes were cheaply available and media channels were very inefficient. d)cigarette manufacturers were trying hard to bring an alternative into the market

Abar magnet cut in half will form a total ofpoles. a)fourb)eightc)two

Debris produced by mining is called