A block of mass 10 kg slides with velocity of 10 m/s on a rough horizontal surface. It comes to rest after covering a distance of 50 meters. Find the frictional force.
10N
u = 10m/s
v = 0
s = 50
v2- u2 = 2as
a = -1 m/ s2
Friction from is providing this deceleration of the block
fr = ma
fr = 10 × 1
fr = 10N
so friction is 10N in backward direction.