Por favor ayudeneme... es sobre fisica y quimica

Atrain departs from its station at a constant acceleration of 5 m/s. what is the speed of the train at the end of 20s?

15. one purpose of the tread pattern on a tire is to a reduce tire wear. b. reduce traction c. allow water to flow away from the tire. d. look impressive.

Suppose you have three polarizing filters, with the second at an angle of 42∘ to the first and the third at an angle of 90∘ to the first. by what perfect will the original intensity of unpolarized light be reduced to after passing through all three filters?