The larges grand piano in the world is really grand. Built in London, it has a mass of 1250 kg. Suppose a pianist finishes playing this piano and pushes herself from the piano so that she rolls backwards with a speed of 1.4m/s. Meanwhile, the piano rolls forward so that in 4.0s it travels 24 cm at constant velocity. Assuming the stool that the pianist is istting on has a negligible mass, what is the pianist's mass? a. v of piano= s/t= .24/4=.06m/s b. mp2= -mpvp,f/vp2,f= (-1250*.06)/-1.4 = 54kg Correct me if I'm wrong, thanks!