A30.0 kg object has an initial velocity of 7.00 m/s and a final velocity of 10.0 m/s. the work done on the object is j. (report the answer to three significant figures.)

The work done in the object, in this case, can also be tantamount or equal to the change in the object's kinetic energy (KE) which can be solved through the equation below.
                 KE = 0.5mv² 
where m is mass and v is the velocity.
Substituting the known values from the given,
              KE= 0.5(30)(10² - 7²) = 765 J
Therefore, the answer is 765 J.