Mass And WeightCopy
1. A student on Earth has a mass of 60 kg. On a planet where the gravitational field strength is 3 N/kg, what is her weight?
A) 180 N
B) 600 N
C) 20 N
D) 60 N
2. Which of the following statements is true about mass and weight?
A) Mass changes when gravitational field strength changes.
B) Weight is measured in kilograms.
C) Mass is a force and depends on location.
D) Weight is the force acting on a mass due to gravity.
3. On the Moon, the gravitational field strength is 1.6 N/kg. What is the mass of an object that weighs 16 N on the Moon?
A) 0.1 kg
B) 25 kg
C) 10 kg
D) 1.6 kg
4. If a person weighs 980 N on Earth, their mass is:
A) 100 kg
B) 98 kg
C) 10 kg
D) 9.8 kg
5. Which instrument would most accurately measure weight on Earth?
A) Lever balance
B) Spring balance
C) Electronic beam balance
D) Top pan balance
6. The gravitational field strength on Jupiter is approximately 24.8 N/kg. What is the weight of a 12 kg mass there?
A) 296 N
B) 124.8 N
C) 12 N
D) 248 N
7. A block has a mass of 2.5 kg. Its weight on Earth is:
A) 25 N
B) 2.5 N
C) 0.25 N
D) 24.5 N
8. What causes your weight to change if you go to the top of a very tall mountain?
A) Your mass increases
B) Air pressure changes
C) Gravitational field strength decreases slightly
D) The shape of your body changes
9. The mass of an astronaut is 75 kg. What is their weight on Earth and on the Moon (g = 9.8 N/kg and 1.6 N/kg respectively)?
A) 735 N and 75 N
B) 735 N and 120 N
C) 735 N and 117.6 N
D) 735 N and 480 N
10. If the gravitational field strength of a planet is unknown, but a 20 kg mass weighs 400 N, what is the g on that planet?
A) 2 N/kg
B) 10 N/kg
C) 20 N/kg
D) 0.5 N/kg
11. Which of the following statements about mass is FALSE?
A) Mass is a measure of the amount of matter
B) Mass remains constant everywhere in the universe
C) Mass is measured using a balance
D) Mass can be zero in space
12. Weightlessness in orbit occurs because:
A) There is no gravity in space
B) Mass becomes zero in orbit
C) The spacecraft and astronaut are both in free fall
D) The astronaut’s weight is balanced by normal reaction
13. A spring balance reads 0 N when nothing is hanging from it. When a block is attached, it reads 15 N. If g = 10 N/kg, the block’s mass is:
A) 1.5 kg
B) 15 kg
C) 0.15 kg
D) 150 kg
14. What happens to the weight of a 50 kg object when it is taken from Earth to Mars (g = 3.7 N/kg)?
A) Decreases to 185 N
B) Increases to 500 N
C) Remains at 490 N
D) Changes to 50 N
15. A spring balance is used on the Moon to measure the weight of a mass. Compared to Earth, the reading on the Moon will be:
A) Higher
B) Lower
C) Equal
D) Zero
16. Mass is typically measured in:
A) Newtons
B) Kilograms
C) Joules
D) Pascals
17. Which equation is used to find weight?
A) W = mg
B) W = m/g
C) W = g/m
D) W = m + g
18. The gravitational field strength of Earth is best described as:
A) A scalar quantity
B) A uniform constant everywhere in the universe
C) A force per unit mass
D) Always decreasing with altitude
19. On a distant asteroid, a 10 kg object weighs 50 N. What is the asteroid’s gravitational field strength?
A) 5 N/kg
B) 0.5 N/kg
C) 10 N/kg
D) 50 N/kg
20. Which concept best explains the change in weight when ascending in an elevator?
A) Mass dilation
B) Gravitational field strength shifts
C) Apparent weight variation due to acceleration
D) Gravitational shielding
21. What is the SI unit of weight?
A) Kilogram
B) Newton
C) Joule
D) Dyne
22. If the weight of an object is 0, then:
A) It must have zero mass
B) It is in a vacuum
C) It is free-falling or in zero gravity
D) It is accelerating
23. A satellite in orbit experiences:
A) Zero gravity
B) Balanced mass
C) Constant weight
D) Free-fall condition
24. A 70 kg person on Earth stands on a bathroom scale. It reads 686 N. When the same person is in an elevator accelerating upward, the reading:
A) Stays the same
B) Increases
C) Decreases
D) Becomes zero
25. Which of the following would affect the weight of a body but not its mass?
A) Heating
B) Altitude change
C) Size
D) Density
26. A planet’s gravitational field strength doubles. What happens to the weight of an object?
A) Doubles
B) Triples
C) Halves
D) Remains constant
27. In deep space, a 5 kg object is released. What force acts on it?
A) 49 N
B) 5 N
C) Zero
D) Cannot be determined without g
28. On a scale calibrated in newtons, a reading of 98 N corresponds to what mass on Earth?
A) 9.8 kg
B) 98 kg
C) 10 kg
D) 100 kg
29. A 5 kg mass on Earth has a weight of:
A) 49 N
B) 50 N
C) 500 N
D) 45 N
30. What property of weight makes it a vector quantity?
A) It can be zero in space
B) It has direction and magnitude
C) It is a force
D) It depends on mass
31. A force of 200 N acts on a 40 kg object. What is the gravitational field strength?
A) 5 N/kg
B) 4 N/kg
C) 8 N/kg
D) 2 N/kg
32. Which of these is NOT a method of measuring mass?
A) Top pan balance
B) Spring balance
C) Beam balance
D) Lever balance
33. The reason a spring balance cannot measure mass accurately on different planets is:
A) It measures volume
B) It needs power supply
C) It depends on gravitational field strength
D) It is affected by air pressure
34. Which of the following objects experiences the same gravitational force on Earth and Moon?
A) A falling feather
B) A stationary object
C) A magnet
D) None
35. Which statement best distinguishes weight from mass?
A) Mass is variable; weight is not
B) Mass is dependent on location
C) Weight has direction and is a force
D) Weight remains unchanged
1. A) 180 N
✅ Explanation: Weight = mass × g = 60 × 3 = 180 N
❌ B) 600 N – used Earth’s g (10 N/kg)
❌ C) 20 N – incorrect multiplication
❌ D) 60 N – confused with mass
2. D) Weight is the force acting on a mass due to gravity
✅ Definition of weight
❌ A) Mass is constant, not variable
❌ B) Weight is measured in newtons
❌ C) Mass is not a force
3. C) 10 kg
✅ Explanation: m = W/g = 16 / 1.6 = 10 kg
❌ A) Too low
❌ B) Too high
❌ D) Confused units
4. A) 100 kg
✅ m = W/g = 980 / 9.8 = 100 kg
❌ B) 98 kg – error from incorrect g
❌ C) 10 kg – miscalculation
❌ D) Wrong division
5. B) Spring balance
✅ Measures force (weight)
❌ A, C, D – used for mass, not force
6. A) 296 N
✅ W = mg = 12 × 24.8
❌ B) Confused with Earth’s g
❌ C, D) Underestimated
7. D) 24.5 N
✅ W = 2.5 × 9.8 = 24.5 N
❌ A) Rounded
❌ B, C) Too low
8. C) Gravitational field strength decreases slightly
✅ g decreases with altitude
❌ A) Mass does not change
❌ B, D) Irrelevant to weight
9. C) 735 N and 120 N
✅ Earth: 75×9.8 = 735 N, Moon: 75×1.6 = 120 N
❌ A, B, D – wrong Moon weight
10. C) 20 N/kg
✅ g = W/m = 400/20 = 20 N/kg
❌ A, B, D – wrong math
11. D) Mass can be zero in space
✅ False; mass is never zero
❌ A, B, C – all true
12. C) The spacecraft and astronaut are both in free fall
✅ They accelerate at same rate, hence weightless
❌ A) Gravity is present
❌ B) Mass stays constant
❌ D) No normal reaction in orbit
13. A) 1.5 kg
✅ m = W/g = 15 / 10 = 1.5 kg
❌ Others: incorrect division
14. A) Decreases to 185 N
✅ 50×3.7 = 185 N
❌ B, C, D – wrong g
15. B) Lower
✅ Moon’s g is lower than Earth’s
❌ A, C, D – incorrect
16. B) Kilograms
✅ SI unit of mass
❌ A) Newtons → weight
❌ C) Joules → energy
❌ D) Pascals → pressure
17. A) W = mg
✅ Correct formula
❌ Others: mathematically wrong
18. C) A force per unit mass
✅ g = F/m
❌ A) Scalar → g is vector
❌ B) Varies with location
❌ D) Only slightly with altitude
19. A) 5 N/kg
✅ g = W/m = 50/10
❌ Others: miscalculated
20. C) Apparent weight variation due to acceleration
✅ True cause
❌ Others: unrelated or incorrect physics
21. B) Newton
✅ Unit of force (weight)
❌ A) kg → mass
❌ C) energy
❌ D) CGS unit
22. C) It is free-falling or in zero gravity
✅ Weight = 0 when no support force
❌ A) Mass ≠ 0
❌ B) Gravity may be present
❌ D) Not always true
23. D) Free-fall condition
✅ Satellite and contents accelerate together
❌ A) Gravity still acts
❌ B, C) Confusing terms
24. B) Increases
✅ Apparent weight increases with upward acceleration
❌ A) Only at rest
❌ C, D) Incorrect physics
25. B) Altitude change
✅ Affects g
❌ Others: do not affect weight directly
26. A) Doubles
✅ Weight is directly proportional to g
❌ Others: misunderstand formula
27. C) Zero
✅ No significant gravity in deep space = zero net force
❌ Others: assume Earth-like g
28. C) 10 kg
✅ m = W/g = 98/9.8
❌ Others: miscalculation
29. A) 49 N
✅ 5×9.8
❌ B) Rounded
❌ C) Off by 10×
❌ D) Wrong g
30. B) It has direction and magnitude
✅ Weight = vector
❌ A) Incorrect reasoning
❌ C, D) Not full explanation
31. A) 5 N/kg
✅ g = F/m = 200/40
❌ Others: incorrect division
32. B) Spring balance
✅ Measures weight, not mass
❌ Others: proper mass measuring tools
33. C) It depends on gravitational field strength
✅ Spring balance = force meter
❌ A, B, D – not the issue
34. D) None
✅ All objects have different weights depending on g
❌ Others: have different gravity responses
35. C) Weight has direction and is a force
✅ Weight is vector, mass is scalar
❌ A, B, D – incorrect or reversed