# MCAT Physics

## 27 terms

### Vector

Quantities with magnitude and direction, i.e. velocity, force

### Scalar

Quantities with only magnitude, not direction, i.e. mass, speed

### Displacement

Change in position, regardless of path in between two points

∆x / ∆t, (m/s)

∆v/ ∆t, (m/s^2)

### Linear Motion Equations

Vf^2=Vi^2 + 2a∆x
Vf = Vi + at
∆x = Vit + 1/2at^2
∆x = (vf+vi/2) t

### Vertical and horizontal components of velocity

Vertical = v sin ø
Horizontal = v cos ø

### Static Friction

Need to overcome static friction to move.
0≤ Fs≤ µsN

### Kinetic Friction

Opposes objects in motion. Fk=µkN

### Newtons 1st Law

Objects in motion or at rest will stay like that unless a net force is acting on them

### Newtons 2nd Law

Net force on an object will cause net acceleration in that direction. F = ma. Units: N, kg•m/s^2. If the force of gravity is more than the force of the parachute, person will accelerate down. IF they are equal, terminal velocity has been reached.

### Newton's 3rd Law

Every force has an opposite and equal force.

### Gravitation

Any two objects exert an attractive force on each other, Fg = Gm1m2 / r^2

### Uniform Circular Motion

Acceleration and force are directed into the circle, velocity is tangent. a = v^2 / r, Fc = mv^2/r

### Equilibirum

An object is at equilibrium when the sum of the forces acting on it is 0

### Work

For a constant force F which is moved over a distance d, W = FD cos ø, if force is perpindicular to displacement, work is zero. Unit: Joule ( N • m)

### Power

The amount of work in a certain time. P=W/t, Unit: Watt (Joules/sec)

### Energy characteristics

Scalar quantity, Joule

### Kinetic Energy

Energy of object in motion, KE = 1/2 mv^2

### Potential Energy

Energy of an object based on position, gravitational PE = mgh

### Total Mechanical Energy

E = U + K, If this value is constant, then energy is conserved if there are no NC forces.

### Work/Energy theorm

Relates all forces that do work on an object and kinetic energy. For a specified amount of time, W = ∆ KE

p = mv

### Elastic Collision

Momentum and kinetic energy conserved

### Inelastic Collision

Momentum but not KE conserved

### COmpletely inelastic collision

Momentum but not KE conserved, and the objects stick together after collision

### Impulse

∆P, change in momentum. Impulse = Ft