A block of mass 4 kg is placed on a rough horizontal plane. A time dependent horzontal force F = kt acts on the block (k = 2 N/s). Find the frictional force between the block and the plane at t = 2 second and t = 5 second (mu = 0.2)

A block of mass 4 kg is placed on a rough horizontal plane. A time dep

1.	A block of mass 4 kg is placed on a rough horizontal plane. A time dependent horzontal force F = kt acts on the block (k = 2 N/s). Find the frictional force between the block and the plane at t = 2 second and t = 5 second (mu = 0.2)
Answer» SOLUTION :When t = 2 SEC F = 4N `f_(ms)=mu_(s)mg = 0.2xx4xx10=8N` `THEREFORE F lt f_(ms) therefore` friction = 4 N When t = 5 sec F = 2 (5) = 10 N `F gt f "" therefore` friction = 8 N.