# Physik ## MomentumZurück zur Themenübersicht

### Forces

• Balanced Force = Steady speed or at rest
• Unbalanced Force = acceleration/deceleration
• Either accelerate or

### Variables

• P = Momentum = kgm/s
• m = Mass = kg
• V = Velocity = m/s

### Formula

• P = m * V
• m = P / V
• V = P / m

Mass in motion:
How many Kg's are put into otion devided by seconds.

### What happens if you double the mass or velocity?

If you either double the mass or the velocity the momentum will also double.

### Any change in momentum can be written as:

• Δp = m * Δv
• Δp = m * a * Δt
• Δp = m * a * Δt
• Δp = F * Δt

### Impulse

• Change in momentum: Δp
• Overall effect of a force acting over time
• Symbol: J (N/s (Newton-seconds))
• Constant Force: J = F * Δt
• Net impulse: all forces on an object
• Net impulse formula: Jn = Δp = FΔt
•                                            ↳ pf - pi
•                                            ↳ m*vf - m*vi
• Beispiel:                             (0,2kg)*(5m/s) - (0,2kg)*(-10m/s)
•                                            = 1kg m/s - (-2kg m/s)
•                                            = 3kg m/s
• The minus sign is important, as momentum is a vector, there is a positive and negative direction.
• It has to be thought that there is a x and y direction, only 1 is calculated
• We can go back again:
• Net impulse formula: Jn = Δp = FΔt
•                                   3kg m/s = Fnx * (0,02s)
•                                   Fn = (3kg m/s) / 0,02s = 150N

Review

• v1 = 20 m/s
• m1 = 10kg
• Momentum: 20*10 = 200kgm/s

• v2 = 10m/s
• m2 = 20kg
• Momentum: 10*20 = 200kgm/s

• Total Momentum: 200 + 200 = 400kgm/s
• Drawing (before collision):
20m/s          10m/s
• o-------->O ------->E
• If these 2 collide the momentum of the 2 balls must equal the momentum of the start

• After Collision:
15m/s         ? m/s
• o------>O -------> E
• 150kgm/s + ? = 400kgm/s
• ? = 400kgm/s - 150kgm/s = 250kgm/s
• v = P/m = 250/20 = 12,5m/s
• Starting Energy is conserved

Force = ___kg * 9,82 = N

Work (Joules) = Force * distance

Power = Joules / t

### The Physical action of applying or transferring energy arround in a system at different scales.

• movement
• pressure
• m*v
• momentum
• action and reaction
• machines
• acceleration
• chemical reaction
• wight → mass
• turning force
• impulse
• moments
• work
• power
• strength
• push and pull

Motion

↓ Momentum

Force

↓ Moments

Work

↓ Time & Work

Power

Piviot: point of turn. Example: Opening a coke with a piece of metal. Piviot is where the glass and the metal touches

The longer the piece the less Force is needed, but more distance is to overcome.