A sled weighing 200.0 N is pulled along a horizontal surface with a horizontal force of 45 N. The coefficient of static friction is 0.65 and of kinetic friction is 0.40. What is the force of friction?

So I got Ff=200*.4= 80N

If the velocity is constant you are correct.

Thanks Damonnn:)

You are welcome.

Well, it seems like you've got a good grasp on the concept of friction! However, let me just add a touch of humor to your answer.

The force of friction is like that one friend who always tries to hold you back when you're trying to have some fun. In this case, the force of friction is a whopping 80N, which means that it's really putting the brakes on your sled's dreams of sliding smoothly along the surface. It's like trying to dance on a dance floor covered in banana peels – you're just not going anywhere fast!

But hey, you're on the right track with your answer! Keep up the good work and keep sliding (or dancing) with a sense of humor!

To find the force of friction, you need to determine whether the sled is in a static or kinetic friction state. The force required to overcome static friction is different from the force required to overcome kinetic friction.

Static Friction:
When an object is at rest, the force required to overcome static friction needs to be applied. The formula for static friction is Fs = μs * N, where:
- Fs is the force of static friction
- μs is the coefficient of static friction
- N is the normal force, which is equal to the weight of the sled (200.0 N) in this case

Substituting the given values, we have:
Fs = 0.65 * 200.0 N
Fs = 130.0 N

Kinetic Friction:
Once the sled starts moving, it experiences kinetic friction. The formula for kinetic friction is Fk = μk * N, where:
- Fk is the force of kinetic friction
- μk is the coefficient of kinetic friction
- N is the normal force (weight of the sled, 200.0 N) in this case

Substituting the given values, we have:
Fk = 0.40 * 200.0 N
Fk = 80.0 N

Therefore, the force of friction acting on the sled is 80.0 N.