In your own words explain coefficient of friction?

An object dropped from cliff falls with a constant acceleration of 10 metre per second square find its speed of two seconds after it was dropped

Acar starts from rest at a stop sign and reaches a velocity of 25 m/s w in 4 seconds. determine the acceleration of the car. question 3 options: a) 6,25 m/s2 b)6.25 m/s c)100 m/s2 d)100 m/s

Ascientist notices that an oil slick floating on water when viewed from above has many different colors reflecting off the surface, making it look rainbow-like (an effect known as iridescence). she aims a spectrometer at a particular spot and measures the wavelength to be 750 nm (in air). the index of refraction of water is 1.3