The 200kg block is originally at rest on the ground Static f

Solution

in vertical,

N - mg = 0

N = mg

and maximum static friction force, fmax = us N = us mg

fmax = 0.45 x 200 x 9.8 = 882 N

if applied force is less than fmax, then block will not move.

P = 1000 N

this greater than fmax. hence block will accelerate and kinetic friction will act.

fk = uk N = 0.35 x 200 x 9.8 = 686 N

Fnet = ma

1000 - 686 = 200a

a = 1.57 m/s^2 ......Ans

When P = 700 N

this less than fmax. hence block will not move

a = 0

when P = 300 N

this is also less then Fmax.

a = 0