NapkinCalc

Physics 1 — Motion & Energy

Motion with constant acceleration

ELI5: if your acceleration is steady, just two equations tell you everything:

  • v = v₀ + a·t — how fast you end up
  • d = v₀·t + ½·a·t² — how far you travel.

The first is "speed builds at a steady rate"; the second adds up all those speeds over time.

v0:=4m/sv_{0} := 4 m/s = 4 m / s initial velocity
ax:=2m/s2a_{x} := 2 m/s^2 = 2 m / s^2 constant acceleration
t1:=3st_{1} := 3 s = 3 s elapsed time
v1=v0+axt1v_{1} = v_{0} + a_{x} \cdot t_{1} = 10 m / s velocity after t₁
d1=v0t1+12axt12d_{1} = v_{0} \cdot t_{1} + \frac{1}{2} \cdot a_{x} \cdot t_{1}^{2} = 21 m distance covered

Real-world hook: this is the math of a car merging onto a highway, a plane's takeoff roll, and the 0–60 mph time in every car review.

Try it yourself: a car starts at 4 m/s and accelerates at 2 m/s² for 5 s. What is its final velocity? (v = v₀ + a·t.)

vfinal:=4m/s+2m/s25sv_{final} := 4 m/s + 2 m/s^2 * 5 s = 14 m / s ✏️ Your turn: compute v = 4 m/s + (2 m/s²)(5 s). Keep the unit on your answer (m/s).
✓ pass abs(vfinal(4m/s+2m/s25s))<0.01m/sabs(v_{final} - (4 m/s + 2 m/s^2 * 5 s)) < 0.01 m/s green when your final velocity is correct