A constant force if 600 N is applied straight up on a 500 kg crate. How long will it take for the crate to rise 8.0 m from rest?

Question

anonymous · Answer

as F=MA i.e. mass*acceleration
so from the given data 
A=F/M=600/500=1.2ms^-2
using equation of motions i.e. s=ut+1/2(at^2)
where s= displacement in meter
u=initial speed
t=time
a=acceleration
so, 8=1/2(1.2*t^2)>>>>as u=0 given at rest initially
16/1.2=t^2
t=3.65148seconds
:)

anonymous · Answer

can you explain the first equation? i'm kinda having a brain fart! D:

anonymous · Answer

newton law F=ma
force=mass*acceleration