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MECHANICS

Newton's First Law of Motion: Inertia

Linear Motion

Newton's Second Law: Force and Acceleration

Newton's Third Law: Action and Reaction

Momentum

Energy

Rotational Motion

Gravity

Projectile and Satellite Motion

Newton's First Law of Motion: Inertia

Linear Motion

Newton's Second Law: Force and Acceleration

Newton's Third Law: Action and Reaction

Momentum

Energy

Rotational Motion

Gravity

Projectile and Satellite Motion

Newton's Third Law: Action and Reaction

For every action there is an equal and opposite reaction. Forces always occur in pairs.

Mass A (kg)

Mass B (kg)

Push strength (N)

10

Forces

FA←B=−FB←AF_{A \leftarrow B} = -F_{B \leftarrow A}
∣FA←B∣=∣FB←A∣|F_{A \leftarrow B}| = |F_{B \leftarrow A}|

These forces are equal in magnitude and opposite in direction.

Acceleration

aA=F/mA(blue),aB=F/mB(green)a_A = F / m_A \quad \text{(blue)},\qquad a_B = F / m_B \quad \text{(green)}
vA=0.00 m/s,aA=0.00 m/s2v_A = 0.00\,\mathrm{m/s},\quad a_A = 0.00\,\mathrm{m/s}^2vB=0.00 m/s,aB=0.00 m/s2v_B = 0.00\,\mathrm{m/s},\quad a_B = 0.00\,\mathrm{m/s}^2
F=10.00 N,mA=2.00 kg,mB=2.00 kgF = 10.00\,\mathrm{N},\quad m_A = 2.00\,\mathrm{kg},\quad m_B = 2.00\,\mathrm{kg}

Interpretation

  • If mass increases, acceleration decreases.
  • Both skaters feel the same force.
  • Different motion is due to different mass.