AHMED SALAMAGRADE 9 · FORCES EXPLORER · DESIGNED BY AHMED SALAMA
Cambridge IGCSE Physics 0625

One object · Earth versus Moon

PREDICT → COMPARE → EXPLAIN

What changes when the same object is moved to the Moon: mass, weight, or both?

EARTH

6 kgg = 9.8 N/kg
mass6 kg
weight58.8 N

MOON

6 kgg = 1.6 N/kg
mass6 kg
weight9.6 N
W = m × g   ·   same mass, different gravitational field strength

Two forces · one acceleration

PREDICT → START → OBSERVE

The push acts right; friction acts left. What happens when the resultant force changes?

resultant force10 N →
acceleration2.5 m/s²
speed at t0.0 m/s
distance at t0.0 m
simulation t = 0.0 s

Simplified model: from rest, constant forces until 60 m. Friction opposes the push and cannot exceed it. Animation time is compressed; displayed time, speed and distance use a = F/m.

Same resultant force · different masses

PREDICT → RUN TOGETHER → EXPLAIN

Two trolleys start from rest. Which one accelerates more when the resultant force is the same?

Same push → 14 NSame friction ← 2 NSame resultant → 12 N

TROLLEY A · 2 kg

acceleration?
distance at t0.0 m

TROLLEY B · 6 kg

acceleration?
distance at t0.0 m
simulation t = 0.0 s

Simplified model: both start from rest with the same constant resultant force. Distances are compared at the same time; each trolley stops at the end of its 60 m track.