A crate starts from rest and is pulled by a force P of 500 N. Determine the speed of the crate after 4 s if between crate and surface is 0.2. Take mass of crate as 80 kg. REMEMBER: use Fdt = m(v -v) and Fdt = m(v -v) to solve this, Use Impulse-momentum method to solve this question. 30 P