Physics: Mass Density Weight Flashcards
Explain what is MASS
Mass is the amount of matter in an object.
What is the measure of Mass?
Mass is measured in kilograms (kg).
Explain what is Weight?
Weight is a force due to the pull of gravity on an object
What is the measure of Weight?
Weight is a force and so is measured in newtons (N).
Explain what is Density
Density describes how closely packed the particles are in a solid, liquid or gas.
Density is the amount of mass per unit volume.
Density is a measure of the mass in a given volume of a substance. It can be calculated using a equation:
How is Density calculated?
Density is a measure of the mass in a given volume of a substance. It can be calculated using the equation:
Density = Mass / Volume
What is the measure of Density?
Density is measured in kilograms per metre cubed (kg/m³)
What is the measure of Volume?
Volume is measured in metres cubed (m³)
Explan what is Volume
The volume of a three-dimensional shape is a measure of the amount of space or capacity it occupies, eg an average can of fizzy drink has a volume of 330 ml.
What is the formula for calculating weight?
The following equation can be used to calculate the weight of an object:
Weight = mass (kg) x gravitational field strength (N/kg)
Explain what is gravitational field strength here on Earth
Gravitational field strengthis the force with which tje planet Earth attracts any object towards it’s centre.
The gravitational field strength on Earth is 10 N/kg.
This means that a 1 kg mass would be attracted to Earth by a force of 10 N
What is the gravitational field strength on Earth?
The gravitational field strength on Earth is 10 N/kg.
This means that a 1 kg mass would be attracted to Earth by a force of 10 N
Calculate the weight:
An apple has a mass of 0.2 kg. Calculate the weight of the apple on Earth (g = 10 N/kg).
W = ?
m = 0.2 kg
g = 10 N/kg
Use the weight equation: W = M x g
and substitute in the values you know:
W = 0.2 x 10
The weight of the apple on Earth is 2 N.
How to calculate mass
A big textbook weighs 90 N. Calculate the mass of the book (g = 10 N/kg).
W = 90 N
m = ?
g = 10 N/kg
Remember to use the equation: W = m x g
Substitute in the values you know: 90 = m x 10
Now divide both sides by 10: 90//10 = (m x 10) / 10
9 = m
The mass of the book is 9 kg.
A student has a mass of 45 kg. The gravitational field strength on Earth is 10 N/kg. What is the weight of the student?
This is calculated by multiplying their mass by the gravitational field strength.
45 x 10 = 450.
The weight of the student is 450 N.
Explain what is WEIGHT
Weight is a result of gravity interacting with mass. This means that an object’s weight will change depending on the strength of the gravitational field acting on it.
What is a NEWTON METER used for?
A force meter, also called a newton meter, is used to measure forces
What is the key difference between MASS and WEIGHT?
the mass of an object is constant but its weight depends on the gravitational force.
Convert from kg/m3 to g/cm3,
To convert from kg/m3 to g/cm3, divide by 1,000.
Convert from g/cm3 to kg/m3
To convert from g/cm3 to kg/m3, multiply by 1,000.
What is the equivalent of 1g/cm3 in kilograms?
Calculating density using grams and cubic centimetres would give a density unit of grams per cubic centimetre (g/cm³).
1 g/cm3 is equal to 1,000 kg/m3
Iron has a density of 7.9 g/cm3 what is this in kg/m3 ?
Iron has a density of 7.9 g/cm3 what is this in kg/m3 ?
7.9 multiplied by 1,000 gives 7,900 kg/m3.
What is the density of an object in kg/m3 if it is 6.531 g/cm3 ?
6.531 multiplied by 1,000 would give 6,531 kg/m3.
To calculate density, the _________ of the material must be known.
To calculate density, the volume of the material must be known.
