Compound Measures & Unit Conversions

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Corbett MathsSpeed, distance and time

Corbett MathsDensity and pressure

GCSE Maths TutorSpeed Distance & Time - Journey Mixtures | Grade 5+ Series | GCSE Maths Tutor

GCSE Maths TutorDensity Mass and Volume Exam Style Questions | Compound Measures | Grade 5+ | GCSE Maths Tutor

Key facts & methods

Speed, distance and time

Speed = Distance ÷ Time. Distance = Speed × Time. Time = Distance ÷ Speed.
Use the SDT triangle: cover what you want to find.
Units must match: if speed is in km/h and time in minutes, convert to hours first.
Average speed = total distance ÷ total time. Not the average of two speeds.
Acceleration = change in speed ÷ time.

Density, pressure and other compound measures

Density = Mass ÷ Volume. Mass = Density × Volume. Volume = Mass ÷ Density.
Units: kg/m³ or g/cm³. 1 g/cm³ = 1000 kg/m³.
Pressure = Force ÷ Area. Units: N/m² = Pa (pascals).
Population density = population ÷ area.
Currency: multiply or divide by the exchange rate. E.g. if £1 = €1.15, then £50 = 50 × 1.15 = €57.50.

Exam questions — 0 questions · 0 marks · Edexcel 4MA1 style

3 marksSpeed calculation4MA1 style 🔢 Calculator

A train travels 240 km in 1 hour 45 minutes. (a) Calculate the average speed in km/h. (b) At this speed, how long (in minutes) would it take to travel 100 km? (3 marks)

Hint: (a) Convert 1h 45min to hours (1.75 h). Speed = distance ÷ time. (b) Time = distance ÷ speed. Convert hours back to minutes (×60).

+30 XP

3 marksDensity problem4MA1 style 🔢 Calculator

A solid metal block has mass 5.4 kg and dimensions 15 cm × 10 cm × 4 cm. Calculate the density of the metal in g/cm³. (3 marks)

Hint: Volume = l × w × h. Convert mass to grams (×1000). Density = mass ÷ volume. Check units — must be g/cm³.

+30 XP

1 markCurrency conversion4MA1 style

The exchange rate is £1 = $1.28. How many pounds is $320?

A £409.60

B £250.00

C £321.28

D £25.00

1 markAverage speed trap4MA1 style

A car travels 60 km at 30 km/h, then 60 km at 60 km/h. What is the average speed for the whole journey?

A 45 km/h

B 40 km/h

C 50 km/h

D 42 km/h

Compound Measures & Unit Conversions

Speed, distance and time

Density, pressure and other compound measures

Module complete! 🎉