A Stuffed Toy With A Mass Of 0.900 Kilograms Sits On The Edge Of A Bed At A Height Of 0.830 Meters. If The Toy Falls Off The Bed, What Will Its Mechanical Energy Be At A Height Of 0.500 Meters? (Ignore Frictional Effects.)

When at a hight of 0.500m, v=gt, S=1/2 gt^2, 0.330=(1/2)*10*t^2, so t=0.26s, then, v=2.6m/s

the kinetic energy is (1/2)mv^2=0.5*0.900*(2.6)^2=3.042.
The potential energy  is mgh=0.900*10*0.330=2.97
so the mechanical energy is 3.042+2.97=6.012J.