3. A warehouse employee is pushing a 30.0 kg desk across a floor at a constant speed of 0.50 m/s. How much work must the employee do on
the desk to change the speed to 1.00 m/s?

The employee must do 11.2308 Joules of work

Explanation:

Work done = force × distance

But  

Force = ma(mass x acceleration due to gravity)

F = 30×9.8

F = 294N

Also distance moved can be found using  the equation  

v² = u² +2gS

1.00 ² = 0.50²+2(9.8)S

1 =0.25+19.6S

1-0.25 =19.6S

0.75=19.6S

S=0.75/19.6

S = 0.0382m

Work done = force × distance = FS

Work done = 294 N X 0.0382m

Workdone =11.2308Nm = 11.2308 Joules

that the claims meet official rules.

don't misinterpret the claims

3. dark matter

empty space could also be a simple vacuum