Question

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 kinetic energy be at a height of 0.500 meters?

Answer 1

PE @ 0.5m = mgh = 4.41 J
KE @ 0.5m = 0.5mv^2 = 2.91 J
ME @ 0.5m = 4.41 + 2.91 = 7.32 J

7.32 J

Answer 2

Answer:Kinetic energy at 0.500 m is 2.9106 Joules.

Explanation:

Mass of the stuffed toy = 0.900 kg

Height at which toy is sitting = 0.830 m

Potential energy at this point will be maximum and kinetic energy will be minimum.

P.E= $0.900 kg\times 9.8 m/s^2\times 0.830 m=7.3206 J$

But the mechanical energy will remain conserve throughout the system.At 0.830 m the mechanical energy will be

M.E= P.E+K.E = 7.3206 J + 0 J=7.3206 J

Potential energy at 0.500 m

$P.E'=mgh'=0.900 kg\times 9.8 m/s^2\times 0.500 m=4.41 J$

Mechanical energy at this point will remain the same as that of the 0.830 m.

M.E= P.E'+K.E'=7.3206 J=4.41 J+ K.E'

K.E'=2.9106 J

Kinetic energy at 0.500 m is 2.9106 Joules.