Graphs and Equations in Physics

Label each axis with 1) Quantity Position Time (m) (s) Mass Volume (kg) (mL) ) Units3) Scale

If the relationship is linear: Write the equation (3 steps) 1) Calculate the slope 2) identify the intercept 3) Write Vertical variable = (slope) horizontal variable + intercept Mass Volume (kg) (mL) Rise / Run = 125 kg – 50 kg 50 mL – 0 mL = 1.5 kg/mL = 50 kg Always numbers with units Always symbols Mass = (1.5 kg/mL) Volume + 50 kg or M = (1.5 kg/mL) V + 50 kg

Once you have the equation… Mass Volume (kg) (mL) Identify the physical meaning of the slope and vertical intercept. M = (1.5 kg/mL) V + 50 kg Slope means Density Intercept means Mass when volume was 0 mL

Position TIME (m) (s) Write this equation: 1. Slope =50 – 100 m s = - 5 m s 2. Intercept = 100 m 3. Equation: x f =( -5m/s) Δt + 100m

Position TIME (m) (s) x f =( -5m/s) Δt + 100m Specific equation x f =(v) Δt + x i Δx = v = x f - x i ΔtΔt General equation Same as