WASSCE Physics · Paper 1 style

Forces

One sample question with the full working. 6 more in the app, with instant feedback and repair sessions for the traps below.

Find the resultant force needed to give a mass of 5 kg an acceleration of 2 m s⁻².

A50 N
B7 N
C10 N
D2.5 N

Show the answer and working

Answer: C

F = ma = 5 × 2 = 10 N.

Trap A Confuses mass and weight: Weight is a force: W = mg (N). Mass (kg) is the amount of matter and does not change with g.

Trap B Inverts a formula: Write the defining equation in words first (density = mass per unit volume), then rearrange algebraically. Check units: kg/m³.

Trap D Inverts a formula: Write the defining equation in words first (density = mass per unit volume), then rearrange algebraically. Check units: kg/m³.

Traps in Forces

Confuses mass and weight
Weight is a force: W = mg (N). Mass (kg) is the amount of matter and does not change with g.
Inverts a formula
Write the defining equation in words first (density = mass per unit volume), then rearrange algebraically. Check units: kg/m³.

Practise Forces (6 questions)Send to your class on WhatsApp