If friction develop between `2 kg` block and surface is `K`. Calculate the value of `K`

Two blocks of mass 10 kg and 2 kg are connected by an ideal spring of spring constant 1000 N/m and the system is placed on a horizontal surface as shown. The coefficient of friction between 10 kg block and surface is 0.5 but friction is assumed to be absent between 2 kg and surface. Initially blocks are at rest and spring is unstretched then 2 kg block is displaced by 1 cm to elongate the spring then released. Then the graph representing magnitude of frictional force on 10 kg block and time t is : (Time t is measured from that instant when 2 kg block is released to move)

A block of mass 1kg lies on a horizontal surface in the truck, the coefficient of friction between the block and the surface is 0.6. If the acceleration of the truck is 5ms^(-2) the frictional force acting on the block is

A block of mass 1kg lies on a horizontal surface in a truck. The coefficeint of friction between the block and surface is 0.5. If the acceleration of the truck is 6ms^(-2) the acceleration of the block relative to ground is

A block of mass 1 kg lies on a horizontal surface in a truck. The coefficient of static friction between the block and the surface is 0.6. If the acceleration of the truck is 5m//s^2 , the frictional force acting on the block is…………newtons.