Types of Friction
This type of friction resists the start of motion on a stationary object.
What is static friction?
Friction force equals the coefficient of friction multiplied by this quantity.
What is the normal force?
Brake pads pressing on a wheel convert kinetic energy into this.
What is non-conservative work?
An object sliding down a ramp at constant velocity tells you the net force when including friction is this value.
What is zero?
This is the equation used to calculate the force of kinetic friction.
What is Ffk = uK x Fn?
This type of friction acts on an object already sliding across a surface.
What is kinetic friction?
A 10 kg box with a static friction coefficient of 0.4 requires this many newtons to start sliding.
What is 40 N?
Without friction between shoes and the ground, you could not travel effectively.
What is walk?
Friction removes kinetic energy and eventually brings a sliding object to this.
What is rest?
A surface with a coefficient of kinetic friction of 0.5 and a normal force of 80 N produces this many newtons of friction force.
What is 40N?
The friction acting on a skidding car with locked brakes is this type.
What is kinetic friction?
When you double the normal force on a sliding object, the friction force does this.
What is double (2x)?
A sled moves faster on packed snow than on rough gravel because packed snow has a lower value of this.
What is the coefficient of friction?
On a frictionless surface, a moving hockey puck continues forever because of this law.
What is Newton's first law?
A 20 kg crate slides on a floor with a kinetic friction coefficient of 0.25. The friction force is this many newtons.
What is 50 N?
This type of friction is caused by air resistance.
What is fluid friction?
A 5 kg block with a kinetic friction coefficient of 0.3 experiences this many newtons of friction.
What is 15 N?
A parachute slows a skydiver by dramatically increasing this type of friction from the air.
What is fluid friction?
A car accelerates forward because road friction on the drive tires acts in this direction.
What is forward?
The unit of friction is this.
What is newtons?
Two surfaces in contact but not moving relative to each other experience this, which can exceed kinetic friction.
What is static friction?
Kinetic friction always acts in this direction relative to the object's motion.
What is opposite?
Sweeping in front of a curling stone melts the ice slightly, reducing friction and allowing the stone to do this.
What is travel further?
A skydiver reaches terminal velocity when the upward drag force equals this, resulting in zero acceleration.
What is gravity?
A 15 kg box is pushed across the floor at constant velocity with a force of 45 N. The coefficient of kinetic friction is this value.
What is 0.3?