IGCSE Physics | Practice Test | 25 Questions
Write down the definition of mass.
Write down the definition of weight.
State the unit of mass and the unit of weight.
Write down the equation for gravitational field strength $g$. Define each symbol and state its unit.
State the approximate value and unit of gravitational field strength at the surface of the Earth.
Apart from being a measure of force per unit mass, what else does $g$ represent in terms of motion?
An object is taken from Earth to the Moon. What happens to its mass? Explain your answer.
An object is taken from Earth to the Moon. What happens to its weight? Explain your answer.
Name one piece of equipment used to compare the masses of two objects.
Define what is meant by a gravitational field. Supplement
A bag has a mass of 4 kg. Calculate its weight on Earth. ($g = 9.8\ \text{N/kg}$)
An object weighs 19.6 N on Earth ($g = 9.8\ \text{N/kg}$). Calculate its mass.
A rock weighs 98 N on Earth ($g = 9.8\ \text{N/kg}$). Calculate the mass of the rock.
An astronaut has a mass of 60 kg. Calculate their weight on the Moon, where $g = 1.6\ \text{N/kg}$.
A probe has a mass of 3 kg. Calculate its weight on Mars, where $g = 3.7\ \text{N/kg}$.
An object weighs 44.1 N on Earth ($g = 9.8\ \text{N/kg}$).
(a) Calculate the mass of the object.
(b) Calculate the weight of the object on the Moon ($g = 1.6\ \text{N/kg}$).
Two objects are placed on a beam balance. Object A has a mass of 500 g. Object B also has a mass of 500 g.
(a) What does the balance show on Earth?
(b) The same experiment is repeated on the Moon. What does the balance show? Explain why.
A space probe on the Moon has a weight of 24 N ($g_\text{Moon} = 1.6\ \text{N/kg}$).
(a) Calculate the mass of the probe.
(b) Calculate the weight of the probe on Earth ($g = 9.8\ \text{N/kg}$).
Calculate the weight of a 25 kg object on a planet where $g = 12\ \text{N/kg}$.
A student’s weight on Earth is 637 N ($g = 9.8\ \text{N/kg}$). Calculate their mass.
An astronaut has a mass of 80 kg.
(a) Calculate the astronaut’s weight on Earth ($g = 9.8\ \text{N/kg}$).
(b) Calculate the astronaut’s weight on the Moon ($g = 1.6\ \text{N/kg}$).
(c) The astronaut is weighed using a beam balance on the Moon. Will the reading be different from on Earth? Explain your answer.
A student makes the following statement: “My mass is 50 kg on Earth. So on the Moon my mass must be less, because the Moon’s gravity is weaker.”
(a) Identify and explain the scientific error in the student’s statement.
(b) Calculate the student’s weight on Earth ($g = 9.8\ \text{N/kg}$).
(c) Calculate the student’s weight on the Moon ($g = 1.6\ \text{N/kg}$).
An object has a weight of 78.4 N on Earth ($g = 9.8\ \text{N/kg}$).
(a) Calculate the mass of the object.
(b) Calculate the weight of the object on a planet where $g = 6.2\ \text{N/kg}$.
(c) Explain, using the concept of gravitational field strength, why the weight is different on this planet compared to Earth. Supplement
Supplement
(a) State what a gravitational field is and describe how it affects a mass placed within it.
(b) Explain how weight is the effect of a gravitational field on a mass.
(c) An object has a mass of 2 kg. It is taken to deep space, far from any planet, where $g \approx 0\ \text{N/kg}$. State the weight of the object in deep space. State whether its mass has changed, and explain why.
A new planet is discovered with a gravitational field strength of $g = 4.9\ \text{N/kg}$. A probe of mass 200 kg is sent to this planet. Supplement
(a) Calculate the weight of the probe on the new planet.
(b) Calculate the weight of the same probe on Earth ($g = 9.8\ \text{N/kg}$).
(c) On the new planet, a scientist uses a beam balance to measure the mass of a rock. The balance reads 5 kg. State what the mass of the rock would be on Earth. Explain your reasoning.
