A 50 kg student stands on a 4 kg skateboard at rest. The student catches a 9 kg backpack
moving with a horizontal speed of 2 m/s in the
direction the skateboard is free to roll.

Answerit is comparative because this experiment is comparing the results of the volume at minimal pressure and then increases it; ; ;

Thick and thin filaments

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.