A student investigates the extension of a spring using six different masses. The experimental set-up and data collected are shown below (the student calculated the force from the known mass):

Give more info about the experiment

B   their speed changed during the 25 minutes.

. we do not care the other details; the average velocity is only concerned with the  displacement rather than the  distance traveled. displacement is the change in position, or the "straight-line vector from the initial position to final position".

Accelerating forwards; fa > ff            fn                           |ff< · > fa                      |                     fgfn = fg. so ∑f is just equal to sum of fa and ff (fn and fg cancel)find the distance the pickle travels. v₀ = 0 m/sd = 6.0 mt = 4.0 suse kinematic equationd = v₀t + at²/2d = 0t + at²/2d = at²/2a = 2d/t²a = 2(6.0 m)/(4.0 s)² a = 0.75 m/s² forwards∑f = fa + ffwe are given that ff = 3.8 n backwardsfa = ∑f - fffa = ma - ff fa = (25.0 kg)(0.75 m/s²) - (-3.8n)fa = 22.55 n forwardssow = fa · dw = (22.55 n)(6.0 m)w = 135 jw = 140 jthe work done to move the object is 140 j.