Work in lifting a body and moving it the same distance horizontally (Lab 4)
The aim is to compute and compare the work done in lifting a block vertically at constant speed and in sliding it the same distance uniformly across a table. First measure the block’s weight P with a dynamometer. Lift it uniformly by a height h: F₁ = P, work A₁ = P · h. Then slide the block uniformly across the table over the same distance h: the dynamometer reading equals the friction force F₂, and the work is A₂ = F₂ · h. Usually F₂ is small, so A₂ < A₁: in horizontal motion no work is done against gravity, only against friction. Repeat three times and discuss errors. Work under the teacher’s supervision and keep blocks and loads off your feet.
Table: № | P (N) | h = s (m) | F₂ (N) | A₁ = Ph (J) | A₂ = F₂s (J). Safety: pull the dynamometer slowly, keep the block away from the table edge, load not above 0.5 kg.