Physics Gce O Level, Topical - Mass, Weight, Density

1. An object that has a mass of 15kg on the Earth is taken to the Moon.The gravitational field strength on the Earth is 10N/ kg and on the Moon is 1.6N/ kg. What are the mass and the weight of the object on the Moon?

	mass/kg	weight/N
A	15	24
B	15	150
C	24	15
D	150	24

Q6, Winter 2005

Option 1

Option 2

Option 3

Option 4

When an object is taken to the Moon, its mass remains the same. Therefore, the mass of the object on the Moon is still 15kg. However, the weight of an object depends on the gravitational field strength. Since the gravitational field strength on the Moon is 1.6N/kg, the weight of the object on the Moon can be calculated by multiplying the mass (15kg) by the gravitational field strength (1.6N/kg). Therefore, the weight of the object on the Moon is 24N.

Explanation

When an object is taken to the Moon, its mass remains the same. Therefore, the mass of the object on the Moon is still 15kg. However, the weight of an object depends on the gravitational field strength. Since the gravitational field strength on the Moon is 1.6N/kg, the weight of the object on the Moon can be calculated by multiplying the mass (15kg) by the gravitational field strength (1.6N/kg). Therefore, the weight of the object on the Moon is 24N.

2. A student does an experiment to estimate the density of an irregularly-shaped stone.Which items of equipment are needed?
A) a balance and a measuring cylinder containing water
B) a balance and a ruler
C) a ruler and a measuring cylinder containing water
D) only a measuring cylinder containing water
Q6, Summer 2007

Option 1

Option 2

Option 3

Option 4

To estimate the density of an irregularly-shaped stone, a balance is needed to measure the mass of the stone. A measuring cylinder containing water is also needed to measure the volume of the stone. By dividing the mass of the stone by its volume, the density can be calculated. Therefore, option A, which includes both a balance and a measuring cylinder containing water, is the correct answer.

Explanation

To estimate the density of an irregularly-shaped stone, a balance is needed to measure the mass of the stone. A measuring cylinder containing water is also needed to measure the volume of the stone. By dividing the mass of the stone by its volume, the density can be calculated. Therefore, option A, which includes both a balance and a measuring cylinder containing water, is the correct answer.

3. A person of weight 600 N at the bottom of a mountain climbs to the top. The gravitational field strength changes from 10.00 N / kg at the bottom to 9.97 N / kg at the top. His mass is unchanged as he climbs.What are his mass and his weight at the top of the mountain?

	mass at top of mountain/ kg	weight at top of mountain/N
A	60.0	598
B	60.0	600
C	60.1	598
D	60.1	600

Q7, Winter 2010, Variant 1

Option 1

Option 2

Option 3

Option 4

As the person's mass is unchanged, his mass at the top of the mountain will also be 60.0 kg. The weight of an object is given by the equation weight = mass x gravitational field strength. Since the gravitational field strength decreases from 10.00 N/kg at the bottom to 9.97 N/kg at the top, the person's weight at the top of the mountain will be slightly less than 600 N. Therefore, the correct answer is option 1, with a mass of 60.0 kg and a weight of 598 N at the top of the mountain.

Explanation

As the person's mass is unchanged, his mass at the top of the mountain will also be 60.0 kg. The weight of an object is given by the equation weight = mass x gravitational field strength. Since the gravitational field strength decreases from 10.00 N/kg at the bottom to 9.97 N/kg at the top, the person's weight at the top of the mountain will be slightly less than 600 N. Therefore, the correct answer is option 1, with a mass of 60.0 kg and a weight of 598 N at the top of the mountain.

4. Three objects are cut from the same sheet of steel. They are different shapes but they all have the same mass

Which object has the greatest density?
A) the disc
B) the L-shape
C) the square
D) they all have the same density
Q6, Winter 2006

Option 1

Option 2

Option 3

Option 4

The three objects are cut from the same sheet of steel and have the same mass. Density is defined as mass divided by volume. Since the objects have the same mass, the object with the greatest density would be the one with the smallest volume. Since the question does not provide any information about the dimensions or volumes of the objects, we can conclude that all three objects have the same density.

Explanation

The three objects are cut from the same sheet of steel and have the same mass. Density is defined as mass divided by volume. Since the objects have the same mass, the object with the greatest density would be the one with the smallest volume. Since the question does not provide any information about the dimensions or volumes of the objects, we can conclude that all three objects have the same density.

5. The mass of a measuring cylinder is measured before and after pouring a liquid into it.

What is the density of the liquid?
A) 0.79g/ cm^3
B) 1.3g/ cm^3
C) 1.4g/ cm^3
D) 2.2g/ cm^3
Q6, Winter 2008

Option 1

Option 2

Option 3

Option 4

The density of a substance is defined as its mass divided by its volume. In this question, the mass of the measuring cylinder is measured before and after pouring the liquid into it. By subtracting the mass of the empty measuring cylinder from the mass of the cylinder with the liquid, we can determine the mass of the liquid. To calculate the density, we need to divide this mass by the volume of the liquid. However, the volume of the liquid is not provided in the question. Therefore, it is not possible to determine the density of the liquid based on the information given.

Explanation

The density of a substance is defined as its mass divided by its volume. In this question, the mass of the measuring cylinder is measured before and after pouring the liquid into it. By subtracting the mass of the empty measuring cylinder from the mass of the cylinder with the liquid, we can determine the mass of the liquid. To calculate the density, we need to divide this mass by the volume of the liquid. However, the volume of the liquid is not provided in the question. Therefore, it is not possible to determine the density of the liquid based on the information given.

6. A room measures 4.0m m 3.0m m 2.0m. The density of the air in the room is 1.3kg/m^3.What is the mass of air in the room?
A) 0.054kg
B) 18kg
C) 24kg
D) 31kg
Q7, Winter 2009

Option 1

Option 2

Option 3

Option 4

The mass of air in the room can be calculated using the formula mass = density × volume. The volume of the room is given as 4.0m × 3.0m × 2.0m, which is equal to 24.0m^3. The density of the air is given as 1.3kg/m^3. Therefore, the mass of air in the room is 1.3kg/m^3 × 24.0m^3 = 31.2kg.

Explanation

The mass of air in the room can be calculated using the formula mass = density × volume. The volume of the room is given as 4.0m × 3.0m × 2.0m, which is equal to 24.0m^3. The density of the air is given as 1.3kg/m^3. Therefore, the mass of air in the room is 1.3kg/m^3 × 24.0m^3 = 31.2kg.

7. Some students measure the masses and the volumes of different sized samples of a type of wood. Which graph shows their results?

A
B
C
D
Q5, Summer 2005

Option 1

Option 2

Option 3

Option 4

Option 2 shows a graph with the mass on the y-axis and the volume on the x-axis. This is the most appropriate representation for the students' results as they are measuring the masses and volumes of different sized samples of wood. The graph allows for a clear comparison between the mass and volume of each sample, showing any possible patterns or relationships between the two variables.

Explanation

Option 2 shows a graph with the mass on the y-axis and the volume on the x-axis. This is the most appropriate representation for the students' results as they are measuring the masses and volumes of different sized samples of wood. The graph allows for a clear comparison between the mass and volume of each sample, showing any possible patterns or relationships between the two variables.

8. The weight of a stone is found using a newton meter, and its mass is found using a pan balance.
The experiment is carried out on the Earth and on the Moon.For each meter, is its reading the same or different on the Earth and on the Moon?

	reading on newton meter	reading on pan balance
A	different	different
B	different	same
C	same	different
D	same	same

Q7, Winter 2011, Variant 1

Option 1

Option 2

Option 3

Option 4

The weight of an object is the force exerted on it due to gravity, while the mass of an object is the amount of matter it contains. The reading on a newton meter measures the weight of the stone, which would be different on the Earth and on the Moon due to the difference in gravitational pull. The reading on a pan balance measures the mass of the stone, which would remain the same regardless of the location. Therefore, the correct answer is Option 2 - the reading on the newton meter is different on the Earth and on the Moon, but the reading on the pan balance is the same.

Explanation

The weight of an object is the force exerted on it due to gravity, while the mass of an object is the amount of matter it contains. The reading on a newton meter measures the weight of the stone, which would be different on the Earth and on the Moon due to the difference in gravitational pull. The reading on a pan balance measures the mass of the stone, which would remain the same regardless of the location. Therefore, the correct answer is Option 2 - the reading on the newton meter is different on the Earth and on the Moon, but the reading on the pan balance is the same.

9. A lump of metal has a mass of 210 g. It is lowered into a measuring cylinder containing water. The level of the water rises from 35cm^3 to 140cm^3.

What is the density of the metal?
A) 0.67g/ cm^3
B) 1.5g/ cm^3
C) 2.0g/ cm^3
D) 6.0g/ cm^3
Q6, Summer 2008

Option 1

Option 2

Option 3

Option 4

The density of an object is calculated by dividing its mass by its volume. In this question, the mass of the metal is given as 210 g and the change in volume of the water in the measuring cylinder is given as 140 cm^3 - 35 cm^3 = 105 cm^3. Therefore, the volume of the metal is 105 cm^3. Dividing the mass by the volume, we get 210 g / 105 cm^3 = 2.0 g/cm^3. Therefore, the density of the metal is 2.0 g/cm^3.

Explanation

The density of an object is calculated by dividing its mass by its volume. In this question, the mass of the metal is given as 210 g and the change in volume of the water in the measuring cylinder is given as 140 cm^3 - 35 cm^3 = 105 cm^3. Therefore, the volume of the metal is 105 cm^3. Dividing the mass by the volume, we get 210 g / 105 cm^3 = 2.0 g/cm^3. Therefore, the density of the metal is 2.0 g/cm^3.

10. A measuring cylinder contains 118 cm^3 of water. When a small object is fully immersed in the water, the reading goes up to 132cm^3. The object has a mass of 42g.What is the density of the object?

A
B
C
D
Q7, Summer 2009

Option 1

Option 2

Option 3

Option 4

The density of an object is defined as its mass divided by its volume. In this case, the mass of the object is given as 42g. The change in volume of the water in the measuring cylinder when the object is immersed is 132cm^3 - 118cm^3 = 14cm^3. Therefore, the volume of the object is 14cm^3. To find the density, we divide the mass (42g) by the volume (14cm^3), which gives us a density of 3g/cm^3.

Explanation

The density of an object is defined as its mass divided by its volume. In this case, the mass of the object is given as 42g. The change in volume of the water in the measuring cylinder when the object is immersed is 132cm^3 - 118cm^3 = 14cm^3. Therefore, the volume of the object is 14cm^3. To find the density, we divide the mass (42g) by the volume (14cm^3), which gives us a density of 3g/cm^3.

11. A box has an internal volume of 1000 cm^3. When a solid object is placed in the closed box, the volume of air in the box is 520cm^3.The density of the object is 8.00g/ cm^3.

What is the mass of the object?
A) 60.0g
B) 3840g
C) 4160g
D) 8000g
Q8, Winter 2010, Variant 1

Option 1

Option 2

Option 3

Option 4

The volume of the object can be calculated by subtracting the volume of air in the box from the internal volume of the box: 1000 cm^3 - 520 cm^3 = 480 cm^3.
The mass of the object can be calculated using the formula: mass = density x volume.
Plugging in the given density of 8.00 g/cm^3 and the volume of 480 cm^3, we get: mass = 8.00 g/cm^3 x 480 cm^3 = 3840 g.
Therefore, the correct answer is option 2, 3840g.

Explanation

The volume of the object can be calculated by subtracting the volume of air in the box from the internal volume of the box: 1000 cm^3 - 520 cm^3 = 480 cm^3.
The mass of the object can be calculated using the formula: mass = density x volume.
Plugging in the given density of 8.00 g/cm^3 and the volume of 480 cm^3, we get: mass = 8.00 g/cm^3 x 480 cm^3 = 3840 g.
Therefore, the correct answer is option 2, 3840g.

12. A student is trying to find the density of a stone, but he has mixed up the instruction cards.

What order should the cards be in?
A) 5 → 3 → 6 → 2 → 1 → 4 → 7
B) 1 → 5 → 3 → 6 → 2 → 7 → 4
C) 5 → 6 → 3 → 2 → 1 → 7 → 4
D) 1 → 4 → 5 → 3 → 6 → 2 → 7
Q7, Winter 2005

Option 1

Option 2

Option 3

Option 4

The correct order of the instruction cards should be 1 -> 5 -> 3 -> 6 -> 2 -> 7 -> 4. This is because the student needs to follow a specific sequence of steps to find the density of the stone. Option 2 is the only answer choice that has this correct sequence of cards.

Explanation

The correct order of the instruction cards should be 1 -> 5 -> 3 -> 6 -> 2 -> 7 -> 4. This is because the student needs to follow a specific sequence of steps to find the density of the stone. Option 2 is the only answer choice that has this correct sequence of cards.

13. An object of mass 100g is immersed in water as shown in the diagram.

What is the density of the material from which the object is made?
A) 0.4g/cm^3
B) 0.9g/cm^3
C) 1.1g/cm
D) 2.5g/cm
Q7, Summer 2006

Option 1

Option 2

Option 3

Option 4

The density of a material is equal to its mass divided by its volume. In this question, the object is immersed in water, which means it displaces a certain volume of water equal to its own volume. Since the object has a mass of 100g and it displaces 40cm^3 of water, its density is 100g/40cm^3 = 2.5g/cm^3. Therefore, the correct answer is option D) 2.5g/cm^3.

Explanation

The density of a material is equal to its mass divided by its volume. In this question, the object is immersed in water, which means it displaces a certain volume of water equal to its own volume. Since the object has a mass of 100g and it displaces 40cm^3 of water, its density is 100g/40cm^3 = 2.5g/cm^3. Therefore, the correct answer is option D) 2.5g/cm^3.

14. At a point on the surface of the Earth, the gravitational field strength is 9.8N/ kg.Which pair of values for mass and weight are correct for an object placed at this point?

	mass/kg	weight/N
A	9.8	10
B	10	9.8
C	10	98
D	98	10

Q4, Summer 2005

Option 1

Option 2

Option 3

Option 4

The gravitational field strength at a point on the surface of the Earth is 9.8 N/kg. The weight of an object is given by the formula weight = mass x gravitational field strength. So, for an object placed at this point, if the mass is 10 kg, the weight would be 10 kg x 9.8 N/kg = 98 N. Therefore, Option 3 is correct.

Explanation

The gravitational field strength at a point on the surface of the Earth is 9.8 N/kg. The weight of an object is given by the formula weight = mass x gravitational field strength. So, for an object placed at this point, if the mass is 10 kg, the weight would be 10 kg x 9.8 N/kg = 98 N. Therefore, Option 3 is correct.

15. The diagram shows two objects on a beam balance in equilibrium.

Which need not be the same?
A) the masses of the two objects
B) the moments about the pivot of the two objects
C) the volumes of the two objects
D) the weights of the two objects
Q5, Winter 2008

Option 1

Option 2

Option 3

Option 4

The diagram shows two objects on a beam balance in equilibrium. The question asks which need not be the same. Option 3 states "the volumes of the two objects." This means that the volumes of the two objects can be different and still maintain equilibrium on the beam balance. The masses, moments about the pivot, and weights of the two objects must be equal in order for the beam balance to be in equilibrium.

Explanation

The diagram shows two objects on a beam balance in equilibrium. The question asks which need not be the same. Option 3 states "the volumes of the two objects." This means that the volumes of the two objects can be different and still maintain equilibrium on the beam balance. The masses, moments about the pivot, and weights of the two objects must be equal in order for the beam balance to be in equilibrium.