Calculating Weight Flashcards

All 6 cards in this deck

What is the equation linking weight, mass and gravitational field strength?

$W = m\,g$
weight (N) = mass (kg) × gravitational field strength (N/kg)

What is the value of the gravitational field strength close to the Earth's surface?

About $9.8$ N/kg.

What are the steps to calculate the weight of an object?
e.g. a 2 kg bag where $g = 9.8$ N/kg

1. Write the equation: $W = m\,g$.
2. Put in the values: $W = 2 \times 9.8$.
3. Work out the answer with units: $W = 19.6$ N.

What are the steps to find the mass of an object from its weight?
e.g. weight = 50 N, $g = 10$ N/kg

1. Start from $W = m\,g$.
2. Rearrange: $m = W \div g$.
3. Substitute: $m = 50 \div 10 = 5$ kg.

True or false? Weight is measured in kilograms.

False. Weight is a force, so it is measured in newtons (N); mass is measured in kilograms.

What is the relationship between the weight and the mass of an object?

They are directly proportional — doubling the mass doubles the weight (for the same gravitational field strength).