It's not the frictional force that's needed to start an object at rest into motion. It's actually the force applied to overcome static friction. Here's why:

* Static Friction: This is the friction that prevents an object from moving when it's at rest. It's like a grip that keeps the object in place.

* Force Applied: To start the object moving, you need to apply a force that is greater than the static friction. This force is what overcomes the grip of static friction.

Think of it like this:

Imagine pushing a heavy box. You push gently, but it doesn't budge. That's static friction resisting your force. You push harder, and finally, the box starts to move. You've overcome the static friction.

So, the answer to your question is:

* Frictional force is what you need to overcome, not what you need to start motion.

The amount of force needed to overcome static friction depends on:

* The weight of the object: Heavier objects have more static friction.

* The surface roughness: Rougher surfaces have more static friction.

* The coefficient of static friction: This is a number that describes how strong the grip of static friction is between two surfaces.

Let me know if you have any other questions!