Question

a 50 kg crate is at rest on a level surface the coefficients of friction are 0.3 and 0.4,what is the normal force acting on the crate, a man begins pushing horizontally on the crate how much force must the man exert to start the crate moving, how much force must the man exert to keep the crate moving once it is already in motion, how fast would the crate be moving if he applied that force for 5 seconds, what distance would the crate have covered during that 5 second interval

Answer 1

weight = normal force = m g
= 50 * 9.81 Newtons

static force = .4 * 50 * 9.81
moving force = .3 * 50 * 9.81

assume use entire static force or it will not accelerate

.1*50*9.81 = m a = 50 a
so
a = .981 m/s^2
v = a t = .981 * 5