Aman has a power of 90 w and mass 60 kg runs up a staircase in 40 s. if each staircase is 20cm high find the number of steps? (physics grade 9- gravitation)

Two solutions of the same uv-absorbing molecule were analyzed by uv-vis spectroscopy on the same instrument using 1 cm pathlength cells. use data from the table to calculate by what percentage the concentration of solution b is compared to that of solution a.sample absorbance at 315nm a 0.45 b 0.80