Net force: a force changes velocity, it does not maintain it

Year 11 Physics, Module 2 · crate on a horizontal surface · g = 9.8 m s⁻² · F_net = F_applied − F_friction, a = F_net/m, kinetic friction F_k = μmg · static and kinetic μ taken as equal.

Applied force 0.0 N

Mass 10 kg

Friction μ 0.30

Free-body diagram

applied · friction · weight and normal

Velocity against time

flat line means equilibrium

Press Run. A flat trace means F_net = 0 — the crate keeps moving with no net force.

Readouts

F_applied0.0 N

F_friction0.0 N

F_net0.0 N

a0.000 m/s²

v0.000 m/s

x0.00 m

t0.00 s

weight mg98.0 N

normal N98.0 N

μmg limit29.4 N

Data log

one row per run

#	F_net / N	a / m s⁻²	m / kg

F_net against a

gradient is mass

Log three runs at different forces to fit a line.

Free-body diagram

Velocity against time

Readouts

Data log

Fnet against a

F_net against a