Final answer:
Yes, the force of kinetic friction depends on the weight of the block, as greater weight increases the normal force and hence the kinetic friction, based on the formula f_k = μ_k × N.
Step-by-step explanation:
The force of kinetic friction indeed depends on the weight, or more specifically, the normal force exerted on a block. When trying to slide a heavy crate across a concrete floor, before it starts moving, it is affected by static friction, which adjusts based on the force you apply. Once the crate is in motion, kinetic friction takes over, which is less than static friction. If you increase the mass of the object, like placing a box on the crate, you increase its weight and consequently increase the normal force. The kinetic friction force (f_k) is equal to the coefficient of kinetic friction (μk) times the normal force (N), as described by the equation f_k = μk × N. More weight leads to greater normal force and thus greater kinetic friction. Changes in surface material, like oiling the concrete, change the coefficient of kinetic friction, affecting the force required to keep the crate in motion.