When you are lifting an object... is the work negative?

A6,600 kg train car moving at +2.0 m/s bumps into and locks together with one of mass 5,400kg moving at -3.0m/s. what is their final velocity? +0.50 m/s -1.0 m/s +2.5 m/s -0.25 m/s

In which of the following cases is work being done on an object? question 2 options: pushing against a locked door carrying a box down a corridor pulling a trailer up a hill suspending a heavy weight with a strong

Two polarizers are oriented at 24.0∘ to one another. light polarized at a 12.0-degree angle to each polarizer passes through both. what is the transmitted intensity (%)?