Friction
What is friction?
Friction is a force that resists motion between surfaces (makes things slow down/stop)
What is the formula for work?
W = fd
What is impulse?
The change in momentum of an object.
What is a scalar quantity?
A type of quantity that only has magnitude and no direction.
What is Newton’s first law?
An object at rest stays at rest, and an object in motion stays in motion at the same speed and in the same direction, unless acted on by an external force.
What is the formula for the force of friction.
Ff = µFn
Energy cannot be created or destroyed, only, what?
Transferred or transformed.
What is the formula for impulse?
Impulse = F x change in time
What is a vector quantity?
A quantity that has magnitude and directio.
What is Newton’s second law?
The acceleration of an object depends on the net force acting on it and its mass.
F = ma
In which direction does friction act relative to motion?
The opposite direction of motion.
If there is no motion, how much work is done?
None (0)
What is is formula for momentum?
P = mv
Examples of what type of quantity include mass, temperature, and speed?
Scalars
What is Newton’s third law?
For every action there is an opposite and equal reaction.
Frictions converts mechanical energy in (mostly) what other type of energy?
Thermal (heat) energy
Increasing an objects height increases what type of energy?
Gravitational potential energy.
Which has more momentum: a fast-moving car or a slow-moving truck?
A slow-moving truck.
Examples of what type of quantity include displacement, velocity, and force?
vectors
When you jump off a small boat, the boat moves backward because of what law?
Newton’s third law.
Friction occurs because of microscopic ___ between surfaces.
Irregularities (bumps/ridges)
A student pushes a box with a force of 50 N across the floor for 4 meters in the direction of the force. How much work does the student do on the box?
200J
A 5 kg object changes velocity from 2 m/s to 6 m/s. What is the impulse?
20Ns
The length of a vector can also represent what?
Magnitude.
If you double the force applied to an object but keep its mass the same, what else doubles?
Acceleration.