Speed of a particle at 3rd and 8th second are 20 ms-1and zero respectively, then average acceleration between 3rd and 8th second will be  [JIPMER 2019]

Time interval between 8th and 3rd second,                           Δt = 8 - 3 = 5 s,     i.e.   Δt = 5 sChange in velocity,                         ∆v = 20 - 0  =  20 ms-1∴  Average acceleration =∆v∆t = 205 = 4 ms-2