To calculate the force of kinetic friction acting on the block, we can use the formula:
Frictional force = coefficient of kinetic friction * Normal force
where the normal force is the force exerted by the surface on the block perpendicular to the surface.
In this case, the block has a mass of 20 kg, so its weight (mg) is:
Weight = mass * acceleration due to gravity = 20 kg * 9.8 m/s^2 = 196 N
The normal force is equal in magnitude but opposite in direction to the weight of the block, so the normal force is also 196 N.
Now we can calculate the force of kinetic friction:
Frictional force = coefficient of kinetic friction * Normal force = 0.20 * 196 N = 39.2 N
Therefore, the force of kinetic friction acting on the block is 39.2 Newtons.