Midterm Cheat Sheet
Forces
What Is a Force?
Forces represent the interaction of distinguishable objects.
Specific forces:
The weight W with magnitude W = m * g acts near Earth’s surface with g the gravitational acceleration. (m= mass)
The normal force N is due to contact with a surface. It is directed perpendicular to the surface.
The tension T is due to a taut, massless string. It is directed along the string.
The external contact force Fext acts along the direction of the push.
Unit:
Force and force components: N (Newton) with 1N = 1 kg * m /s2
Mass m: kg (kilogram)
Volume V: m2
Newton’s Laws of Mechanics
Newton’s first law (law of inertia) for an object in mechanical equilibrium: An object at rest remains at rest unless acted upon by a force. An object in motion remains in motion, and at a constant velocity, unless acted upon by a force.
Newton’s second law (equation of motion): The acceleration of a body is directly proportional to, and in the same direction as, the net force acting on the body, and inversely proportional to its mass. Thus, F = ma, where F is the net force acting on the object, m is the mass of the object and a is the acceleration of the object.
Newton’s third law (collision): When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction to that of the first body.
Linear Momentum And Friction
Physical quantities that have a magnitude and a direction in space are described by vectors.
Velocity is speed and direction. Acceleration is increase in speed.
Linear momentum (p) of a single particle (point-like object) in vector notation: p = m * v.
Specific types of friction:
Drag (wind resistance)
Static (maximum occurs right before the object moves) Kinetic (usually less than static)
F friction = u*N (u is just the coefficient of friction)
Terminal Velocity: you stop accelerating because you’ve reached mechanical equilibrium.
The Action of
What Is a Force?
Forces represent the interaction of distinguishable objects.
Specific forces:
The weight W with magnitude W = m * g acts near Earth’s surface with g the gravitational acceleration. (m= mass)
The normal force N is due to contact with a surface. It is directed perpendicular to the surface.
The tension T is due to a taut, massless string. It is directed along the string.
The external contact force Fext acts along the direction of the push.
Unit:
Force and force components: N (Newton) with 1N = 1 kg * m /s2
Mass m: kg (kilogram)
Volume V: m2
Newton’s Laws of Mechanics
Newton’s first law (law of inertia) for an object in mechanical equilibrium: An object at rest remains at rest unless acted upon by a force. An object in motion remains in motion, and at a constant velocity, unless acted upon by a force.
Newton’s second law (equation of motion): The acceleration of a body is directly proportional to, and in the same direction as, the net force acting on the body, and inversely proportional to its mass. Thus, F = ma, where F is the net force acting on the object, m is the mass of the object and a is the acceleration of the object.
Newton’s third law (collision): When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction to that of the first body.
Linear Momentum And Friction
Physical quantities that have a magnitude and a direction in space are described by vectors.
Velocity is speed and direction. Acceleration is increase in speed.
Linear momentum (p) of a single particle (point-like object) in vector notation: p = m * v.
Specific types of friction:
Drag (wind resistance)
Static (maximum occurs right before the object moves) Kinetic (usually less than static)
F friction = u*N (u is just the coefficient of friction)
Terminal Velocity: you stop accelerating because you’ve reached mechanical equilibrium.
The Action of