Hi all, I'm new here on Physics Forums and can't wait to delve into some juicy topics! I have a very practical problem that I need help with. I am doing a home project where I want to move a platform on wheels (loaded to a maximum of 70kg) in a 1.5m long straight line across the floor at a constant, and known velocity . There will be some trial and error before I can define exactly the velocity, but I'm guessing it will be around 1km/hr. So far, I am thinking of attaching the platform to a rope, which can be passed through a roller anchored on the floor to direct the rope to a pulley on the roof which could then be attached to a weight (something like my dodgy diagram!). I'm guessing that the velocity will be somehow determined by the mass of the weight but I'm unsure how to quantify this. Thanks so much, looking forward to hearing your input!