An object is moving at a speed of 20 m/s and has a kinetic energy of 10,000 J. What is the mass of the object?

m=100kg

Explanation:

E=1/2mv^2

10000=1/2m(20)^2

10000=1/2m(400)

10000=1/2m200

50=1/2m

100=m

Each day, my teacher walks the two miles from school to her home
while carrying one fitness log under each arm.  This gives her a great
workout that combines aerobic and strength exercise, and contributes
greatly to her overall fitness. 

Once home, my teacher stacks the fitness logs neatly in her fireplace,
and enjoys a sense of toasty comfort and relaxation until her bedtime.