**Want:**list variable names:- Δt - how long, how much time, time passed
- Δx - how far, change in position or height
- x
_{i}- starting position or height - x
_{f}- ending position or height - v
_{avg}- "**average**" velocity - v
_{i}- starting velocity,*from*this speed, velocity originally going at - v
_{f}- ending velocity,*to*this speed; velocity it hit the ground with - Δv - change in velocity, increase or decrease in speed, v
_{f}- v_{i} - 0 m / s: "at rest", "still", "unmoving", "released" (v
_{i}), "stopped" (v_{f}), ball at top of throw - a - acceleration, change in velocity per second, rate speeding up or slowing down at

- Δt - how long, how much time, time passed
**Have:**Variable names, numbers, units**Convert**everything to m, s, kg using factor-label.

1000 m = 1 km 60 s = 1 min 1000 g = 1 kg

1000 mm = 1 m 60 min = 1 h

100 cm = 1 m

10 mm = 1 cm**Equation**in which you know everything except one of your "wants."Equation Variables Δx = x _{f}- x_{i}Δx, x _{f}, x_{i}Δt = t _{f}- t_{i}Δt, t _{f}, t_{i}Δv = v _{f}- v_{i}Δv, v _{f}, v_{i}v _{avg}= (Δx)/(Δt)v _{avg}, Δx, Δta = (Δv)/(Δt) a, Δv, Δt v _{f}= v_{i}+ aΔta, v _{f}, v_{i}, ΔtΔx = .5(v _{f}+ v_{i})ΔtΔx, v _{f}, v_{i}, ΔtΔx = v _{i}Δt + .5a(Δt)^{2}Δx, Δt, a, v _{i}

Can't find an equation that gets what you want? Find something else you*can*solve for. Having Δt might open up a whole new world of possibilities.**Plug in and solve.**- Don't plug in the units unless you're really comfortable with them - they can confuse you, and you already know what units you expect to come out.
- First
**simplify**any expression that just has numbers in it. Cross out anything times zero. Cross out any "+ 0." - Variable stuck on the bottom? Multiply both sides by it.
- Variable, or square of variable, encumbered by some coefficient multiplied by it? Divide both sides by the coefficient.
- Got the square alone on a side? Square root both sides.