Newton's First Law (Inertia)

An object in motion at constant velocity or at rest will stay that way, unless acted upon by an external force.

Newton's Second Law

F(net) = ma

Newton's Third Law

F(AB) = -F(BA)

Force on X

Product of (mass of X) and (acceleration of X) F=ma

If you have a POSITIVE net acceleration, he normal force must be ( > or < ) m*g

Greater than (>)

*Fill in the blank with: ( > ) or ( < )*

If you have a NEGATIVE net acceleration, the normal force must be _______ m*g

Less than (

F(net) =

F(net) = F(N) - mg = m a(net)

Air resistance

Function of v^2 and k, where "k" is proportional to the density of air and the surface area of the mass.

Kinetic friction

f(k) =u(k)F(n)

Static Force: F(s)

F(s) = F(applied)

Fs(max)

minimum force required to get object to move = u(s)F(n)

Static and kinetic co-efficient relationship

µ_{s} is ALWAYS > µ_{k}

What forces are acting on a box at rest on an inclined plane

f(s) = f(applied) = mgsin(theta)

fs(max)=

u(s)mgcos(theta)

As the angle of an inclined plane (θ ) increases, what happens to the

a) applied force,

b) static force f_{s}

c) MAXIMUM static friction (f_{s,max})?

As θ increases,

a) f_{applied} increases,

b) the static force increases

c) f_{s,max} DECREASES

Gravitational Force

F= (Gm_{1}m_{2})/r^{2 }

*Two masses will exert an attractive force on one another inversely proportional to the square of the distance between them.*

Uniform Circular Motion

The net force on an object moving at a constant speed on a circular path points toward the center of the circle.

F(centripetal)

F(c)=(mv^2)/r

Centripetal Acceleration

a(c) = v^2/2

Circumference of a circle

C = 2(pi)r Conversion: 2(pi)rad = 360 degrees

Theta of a circle (relation to arc length (s) and radius (r) )

theta= s/r

Angular speed (w)

2(pi)f = v/r

Torque

rotational analog of force is a vector Units: Newton meter (N*m) NOTE: Joules are (N*m) but scalar Torque= F*l l=(r)(sin(theta))

Torque rotational convention

Torque > 0: Counterclockwise Torque < 0: Clockwise

Rotational equilibrium

An object is in rotational equilibrium when the sum of the torques acting on it is zero.

Work

Work=Fd cos (theta) SCALAR unit: joules "transfer of energy" N*m = Joules

"Positive Work"

Work done on a system = transfer of energy INTO system. KE goes up

Energy

JOULES Kinetic Energy = (1/2)mv^2

Average Power (Watt)

Watt = Joules/second P=change in energy/change in time P= F*v

Work Energy Theorum

Work(net) = change in KE +work: gain KE -work: lose KE