A rope parallel to the ground pulls a block across ice. The boulder has a mass of 500kg and there are three beefy guys wearing crampons exerting a constant net force of 2000N on the rope. What is the acceleration of the block? How long does it take the boulder to slide 5 meters to the edge of the pond?

Question

experimentx · Answer

theoritically, 
F = m*a
or,  a = 2000/500 = 4 m/s^2

and if initial velocity is 0

solving this equation gives time

5 = 1/2*4*t^2

or t = sqrt(t)

.... however physics don't work this way, it's impossible to apply constant net force of 2000N on a moving body, after it reaches the peak velocity, the net force would be zero ...  (net force -friction = 0) so the body moves at constant velocity

experimentx · Answer

oops sorry .. i would like to take back "impossible" ... we generally don't do so