1 . Who discovered the law of gravity?
A) Albert Einstein
B) Sir Isaac Newton
C) Galileo Galilei
D) Johannes Kepler
Answer: B) Sir Isaac Newton
Explanation: Sir Isaac Newton discovered the law of gravity in 1687.
2 . What is the force of gravity dependent on?
A) Distance between objects
B) Mass of objects
C) Both distance and mass of objects
D) Neither distance nor mass of objects
Answer: C) Both distance and mass of objects
Explanation: The force of gravity is dependent on both the distance between two objects and the mass of the objects.
3 . Which planet has the strongest gravitational pull in our solar system?
A) Earth
B) Jupiter
C) Saturn
D) Mercury
Answer: B) Jupiter
Explanation: Jupiter has the strongest gravitational pull in our solar system.
4 . What is the acceleration due to gravity on Earth?
A) 9.8 m/s^2
B) 8.9 m/s^2
C) 10.2 m/s^2
D) 7.5 m/s^2
Answer: A) 9.8 m/s^2
Explanation: The acceleration due to gravity on Earth is 9.8 m/s^2.
5 . What is the formula for the force of gravity between two objects?
A) F = ma
B) F = GMm/d^2
C) F = mv^2/r
D) F = kx
Answer: B) F = GMm/d^2
Explanation: The formula for the force of gravity between two objects is F = GMm/d^2, where G is the gravitational constant, M and m are the masses of the two objects, and d is the distance between them.
6 . What is the gravitational constant?
A) 6.67 x 10^-11 Nm^2/kg^2
B) 9.81 m/s^2
C) 3.00 x 10^8 m/s
D) 1.38 x 10^-23 J/K
Answer: A) 6.67 x 10^-11 Nm^2/kg^2
Explanation: The gravitational constant is 6.67 x 10^-11 Nm^2/kg^2.
7. What is the relationship between mass and gravity?
A) The more massive an object, the stronger its gravity
B) The less massive an object, the stronger its gravity
C) Mass has no effect on gravity
D) The relationship between mass and gravity is inverse
Answer: A) The more massive an object, the stronger its gravity
Explanation: The more massive an object, the stronger its gravity.
8 . What happens to the force of gravity when the distance between two objects increases?
A) The force of gravity increases
B) The force of gravity decreases
C) The force of gravity remains the same
D) The force of gravity becomes zero
Answer: B) The force of gravity decreases.
Explanation: The force of gravity is inversely proportional to the square of the distance between two objects. This means that as the distance between two objects increases, the force of gravity between them decreases.
9 . What happens to the force of gravity when the mass of one object increases?
A) The force of gravity increases
B) The force of gravity decreases
C) The force of gravity remains the same
D) The force of gravity becomes zero
Answer: A) The force of gravity increases.
Explanation: The force of gravity is directly proportional to the mass of the objects. This means that as the mass of one object increases, the force of gravity between it and another object increases as well.
10 . What is the unit of gravitational force?
A) Newtons
B) Meters
C) Kilograms
D) Joules
Answer: A) Newtons.
Explanation: The unit of gravitational force is newtons (N).
11 . What is the weight of an object with a mass of 50 kg on Earth?
A) 50 N
B) 500 N
C) 490 N
D) 980 N
Answer: D) 980 N.
Explanation: The weight of an object is equal to its mass multiplied by the acceleration due to gravity. On Earth, the acceleration due to gravity is 9.8 m/s^2. Therefore, the weight of an object with a mass of 50 kg on Earth is 50 kg x 9.8 m/s^2 = 490 N.
12 . What is the weight of an object with a mass of 50 kg on the Moon?
A) 50 N
B) 500 N
C) 490 N
D) 196 N
Answer: D) 196 N.
Explanation: The weight of an object on the Moon is less than its weight on Earth because the acceleration due to gravity on the Moon is less than that on Earth. The acceleration due to gravity on the Moon is 1.62 m/s^
13 . Which scientist is credited with discovering the concept of gravity?
A) Isaac Newton
B) Galileo Galilei
C) Albert Einstein
D) Johannes Kepler
Answer: A) Isaac Newton.
Explanation: Isaac Newton is credited with discovering the concept of gravity, which he described in his famous law of universal gravitation.
14 . What is the formula for calculating gravitational force between two objects?
A) F = G(m1m2/d^2)
B) F = ma
C) F = mv^2/r
D) F = mgh
Answer: A) F = G(m1m2/d^2).
Explanation: The formula for calculating gravitational force between two objects is F = G(m1m2/d^2), where F is the force of gravity, G is the gravitational constant, m1 and m2 are the masses of the objects, and d is the distance between them.
15 . What is the gravitational constant?
A) A constant force of gravity between any two objects
B) The force of gravity between the Earth and an object
C) The acceleration due to gravity on Earth
D) A physical constant used in calculations of gravitational force
Answer: D) A physical constant used in calculations of gravitational force.
Explanation: The gravitational constant is a physical constant used in calculations of gravitational force. Its value is approximately 6.674 × 10^-11 Nm^2/kg^2.
16. What is the direction of gravitational force?
A) Always towards the centre of the Earth
B) Always towards the centre of the object with the larger mass
C) Always towards the centre of the object with the smaller mass
D) Always perpendicular to the surface of the Earth
Answer: B) Always towards the centre of the object with the larger mass.
Explanation: Gravitational force is always directed towards the centre of the object with the larger mass, regardless of the relative positions of the objects.
17 . What is the acceleration due to gravity on Earth?
A) 9.8 m/s^2
B) 10 m/s^2
C) 8.9 m/s^2
D) 9.0 m/s^2
Answer: A) 9.8 m/s^2.
Explanation: The acceleration due to gravity on Earth is approximately 9.8 m/s^2.
18 . What is the value of G, the gravitational constant?
A) 9.8 m/s^2
B) 10 m/s^2
C) 6.674 × 10^-11 Nm^2/kg^2
D) 3.00 × 10^8 m/s
Answer: C) 6.674 × 10^-11 Nm^2/kg^2.
Explanation: The value of G, the gravitational constant, is approximately 6.674 × 10^-11 Nm^2/kg^2.
19 . What is the force of gravity between two objects with masses of 100 kg and 200 kg, respectively, that are 5 meters apart?
A) 0.000002 N
B) 0.00002 N
C) 0.002 N
D) 0.02 N
Answer: C) 0.002 N.
Explanation: Using the formula for gravitational force, F = G(m1m2/d^2), where G = 6.674 × 10^-11 Nm^2/kg^2, m1 = 100 kg, m2 = 200 kg, and d = 5 m, we get F = (6.674 × 10^-11 Nm^2/kg^2)(100 kg)(200 kg)/(5^2) = 0.002 N.
20 . What happens to the force of gravity between two objects as the distance between them increases?
A) The force of gravity increases
B) The force of gravity decreases
C) The force of gravity remains constant
D) The force of gravity becomes repulsive
Answer: B) The force of gravity decreases.
Explanation: The force of gravity between two objects decreases as the distance between them increases, according to the inverse-square law of gravity.
21 . What is the relationship between mass and gravitational force?
A) As mass increases, gravitational force decreases
B) As mass increases, gravitational force increases
C) There is no relationship between mass and gravitational force
D) Gravitational force only depends on the distance between the objects
Answer: B) As mass increases, gravitational force increases.
Explanation: The force of gravity between two objects increases as the mass of the objects increases, according to the formula for gravitational force, F = G(m1m2/d^2).
22 . What is the escape velocity of an object on the surface of the Earth?
A) 11.2 km/s
B) 9.8 m/s
C) 299,792,458 m/s
D) 3.00 × 10^8 m/s
Answer: A) 11.2 km/s.
Explanation: The escape velocity of an object on the surface of the Earth is approximately 11.2 km/s.
23 . What is the tidal force?
A) The force that causes the tides on Earth
B) The force that causes objects to float in water
C) The force that causes objects to sink in water
D) The force that causes objects to move in circular motion
Answer: A) The force that causes the tides on Earth.
Explanation: The tidal force is the force that causes the tides on Earth, which is primarily due to the gravitational attraction of the Moon and the Sun.
24 . Which planet has the strongest gravitational pull?
A) Jupiter
B) Earth
C) Mars
D) Saturn
Answer: A) Jupiter.
Explanation: Jupiter has the strongest gravitational pull of any planet in our solar system, due to its large mass.
26 . What is the formula for gravitational potential energy?
A) PE = mgh
B) PE = (Gm1m2)/d
C) PE = (1/2)mv^2
D) PE = -GMm/r
Answer: D) PE = -GMm/r.
Explanation: The formula for gravitational potential energy is PE = -GMm/r, where G is the gravitational constant, M and m are the masses of the two objects, and r is the distance between them.
27 . What is the gravitational force between two objects with masses of 5 kg and 10 kg that are 2 meters apart?
A) 0.001 N
B) 0.002 N
C) 0.005 N
D) 0.01 N
Answer: B) 0.002 N.
Explanation: The gravitational force between two objects with masses of 5 kg and 10 kg that are 2 meters apart is calculated using the formula F = G(m1m2/d^2) = (6.67 × 10^-11 N m^2/kg^2) × (5 kg) × (10 kg)/(2 m)^2 = 0.002 N.
28 . What is the acceleration due to gravity on the surface of the Earth?
A) 9.8 m/s^2
B) 1 m/s^2
C) 299,792,458 m/s^2
D) 3.00 × 10^8 m/s^2
Answer: A) 9.8 m/s^2.
Explanation: The acceleration due to gravity on the surface of the Earth is approximately 9.8 m/s^2.
29 . What is the value of the gravitational constant G?
A) 9.8 m/s^2
B) 6.67 × 10^-11 N m^2/kg^2
C) 299,792,458 m/s
D) 3.00 × 10^8 m/s^2
Answer: B) 6.67 × 10^-11 N m^2/kg^2.
Explanation: The gravitational constant, denoted by G, is approximately equal to 6.67 × 10^-11 N m^2/kg^2.
30 . Which planet in our solar system has the strongest gravitational pull?
A) Jupiter
B) Saturn
C) Earth
D) Venus
Answer: A) Jupiter.
Explanation: Jupiter has the strongest gravitational pull in our solar system due to its large mass.
31 . What is the difference between weight and mass?
A) Weight is a force and mass is a scalar quantity.
B) Weight is a scalar quantity and mass is a force.
C) Weight and mass are both scalar quantities.
D) Weight and mass are both forces.
Answer: A) Weight is a force and mass is a scalar quantity.
Explanation: Weight is the force exerted on an object due to gravity, while mass is the amount of matter in an object and is a scalar quantity.
32 . What is the formula for gravitational potential energy?
A) PE = mgh
B) PE = 1/2mv^2
C) PE = GmM/r
D) PE = Fd
Answer: C) PE = GmM/r.
Explanation: The formula for gravitational potential energy is PE = GmM/r, where G is the gravitational constant, m and M are the masses of the two objects, and r is the distance between them.
33 . Which scientist first proposed the theory of gravity?
A) Isaac Newton
B) Galileo Galilei
C) Albert Einstein
D) Johannes Kepler
Answer: A) Isaac Newton.
Explanation: Isaac Newton first proposed the theory of gravity in the late 1600s, which became the basis for the modern understanding of gravity.
34. Which law states that every object in the universe attracts every other object with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them?
A) Newton’s first law
B) Newton’s second law
C) Newton’s third law
D) Law of universal gravitation
Answer: D) Law of universal gravitation.
Explanation: The law of universal gravitation states that every object in the universe attracts every other object with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
35. How does the gravitational force between two objects change as the distance between them increases?
A) The force remains constant
B) The force decreases
C) The force increases
D) The force becomes zero
Answer: B) The force decreases.
Explanation: The gravitational force between two objects is inversely proportional to the square of the distance between them. As the distance between them increases, the force of gravity decreases.
36 . What is the gravitational force experienced by an object due to the Earth called?
A) Weight
B) Mass
C) Density
D) Volume
Answer: A) Weight.
Explanation: The gravitational force experienced by an object due to the Earth is called weight. It is equal to the product of the mass of the object and the acceleration due to gravity.
37. What is the acceleration due to gravity on Earth?
A) 9.8 m/s
B) 9.8 m/s^2
C) 9.8 m^2/s
D) 9.8 m^2/s^2
Answer: B) 9.8 m/s^2.
Explanation: The acceleration due to gravity on Earth is approximately 9.8 m/s^2, which means that objects in free fall will accelerate at this rate towards the Earth’s surface.
38 . How does the acceleration due to gravity change as an object gets farther away from the Earth’s surface?
A) It remains constant
B) It increases
C) It decreases
D) It becomes zero
Answer: C) It decreases.
Explanation: The acceleration due to gravity decreases as an object gets farther away from the Earth’s surface, following the inverse-square law of gravity.
39 . Which celestial body has the strongest gravitational pull in our solar system?
A) Earth
B) Sun
C) Jupiter
D) Moon
Answer: B) Sun.
Explanation: The Sun has the strongest gravitational pull in our solar system due to its large mass.
40 . . What is the force of gravity experienced by an object called when it is in free fall?
A) Normal force
B) Tension force
C) Gravitational force
D) Weight
Answer: D) Weight.
Explanation: When an object is in free fall, the only force acting on it is the force of gravity. The force experienced by the object due to gravity is called weight.
41 . What is the value of the gravitational constant (G)?
A) 6.67 x 10^-11 N*m^2/kg^2
B) 6.67 x 10^-11 N/kg
C) 6.67 x 10^-11 m^2/s^2
D) 6.67 x 10^-11 m/s
Answer: A) 6.67 x 10^-11 Nm^2/kg^2.
Explanation: The gravitational constant (G) is a fundamental constant of nature that appears in the equation for the force of gravity. Its value is approximately 6.67 x 10^-11 Nm^2/kg^2.
42 . What is the gravitational force experienced by an object on the surface of the Moon compared to that experienced on the surface of the Earth?
A) The same
B) Greater
C) Lesser
D) Zero
Answer: C) Lesser.
Explanation: The gravitational force experienced by an object on the surface of the Moon is lesser than that experienced on the surface of the Earth due to the Moon’s smaller mass and weaker gravitational field.
43 . What is the gravitational force experienced by two objects with masses of 1 kg and 2 kg, respectively, if they are separated by a distance of 3 meters?
A) 1.49 x 10^-11 N
B) 2.98 x 10^-11 N
C) 4.47 x 10^-11 N
D) 8.94 x 10^-11 N
Answer: A) 1.49 x 10^-11 N.
Explanation: The gravitational force between two objects is given by the equation F = G * (m1 * m2) / r^2, where G is the gravitational constant, m1 and m2 are the masses of the two objects, and r is the distance between them. Substituting the given values, we get F = 6.67 x 10^-11 N*m^2/kg^2 * (1 kg * 2 kg) / (3 m)^2 = 1.49 x 10^-11 N.
44 . . What is the gravitational force experienced by two objects with masses of 5 kg and 10 kg, respectively, if they are separated by a distance of 2 meters?
A) 1.11 x 10^-10 N
B) 1.85 x 10^-10 N
C) 2.22 x 10^-10 N
D) 3.70 x 10^-10 N
Answer: B) 1.85 x 10^-10 N.
Explanation: Using the same formula as before, we get F = G * (m1 * m2) / r^2 = 6.67 x 10^-11 N*m^2/kg^2 * (5 kg * 10 kg) / (2 m)^2 = 1.85 x 10^-10 N.
45 . What is the gravitational force experienced by two objects with masses of 50 kg and 100 kg, respectively, if they are separated by a distance of 10 meters?
A) 3.33 x 10^-9 N
B) 6.67 x 10^-9 N
C) 1.33 x 10^-8 N
D) 2.67 x 10^-8 N
Answer: C) 1.33 x 10^-8 N.
Explanation: F = G * (m1 * m2) / r^2 = 6.67 x 10^-11 N*m^2/kg^2 * (50 kg * 100 kg) / (10 m)^2 = 1.33 x 10^-8 N.
46 . What is the acceleration due to gravity on the surface of the Earth?
A) 9.8 m/s^2
B) 10.0 m/s^2
C) 9.0 m/s^2
D) 8.0 m/s^2
Answer: A) 9.8 m/s^2.
Explanation: The acceleration due to gravity on the surface of the Earth is approximately 9.8 m/s^2.
47. What is the gravitational force experienced by a 10 kg object on the surface of the Earth?
A) 10 N
B) 98 N
C) 100 N
D) 980 N
Answer: D) 980 N.
Explanation: The weight of an object is given by the formula W = m * g, where m is the mass of the object and g is the acceleration due to gravity. Substituting the given values, we get W = 10 kg * 9.8 m/s^2 = 980 N.
48. What is the gravitational force experienced by a 50 kg object on the surface of the Earth?
A) 50 N
B) 490 N
C) 500 N
D) 980 N
Answer: D) 490 N.
Explanation: Using the same formula as before, W = m * g = 50 kg * 9.8 m/s^2 = 490 N.
49 . What is the gravitational force experienced by a 1000 kg object on the surface of the Earth?
A) 100 N
B) 980 N
C) 1000 N
D) 9800 N
Answer: B) 980 N.
Explanation: Again, using the formula W = m * g, we get W = 1000 kg * 9.8 m/s^2 = 9800 N.
50 . What is the escape velocity of the Earth?
A) 11.2 km/s
B) 22.4 km/s
C) 33.6 km/s
D) 44.8 km/s
Answer: B) 11.2 km/s.
Explanation: The escape velocity of an object is the minimum velocity needed to escape the gravitational pull of a planet or other celestial body. For the Earth, the escape velocity is approximately 11.2 km/s.
51 . What is the escape velocity of a planet with a mass twice that of the Earth and a radius also twice that of the Earth?
A) 11.2 km/s
B) 15.8 km/s
C) 22.4 km/s
D) 31.6 km/s
Answer: B) 15.8 km/s.
Explanation: The escape velocity of a planet is given by the formula v = √(2GM/r), where G is the gravitational constant, M is the mass of the planet, and r is the radius of the planet. If the mass and radius are both doubled, then the escape velocity becomes v = √(2G(2M)/(2r)) = √(2GM/r), which is the same as the escape velocity for the Earth. Therefore, the answer is B) 15.8 km/s.
52 . What is the gravitational force experienced by a 5 kg object on the surface of a planet with a mass of 2.5 x 10^24 kg and a radius of 6.4 x 10^6 m?
A) 2.01 N
B) 4.02 N
C) 8.04 N
D) 16.08 N
Answer: A) 2.01 N.
Explanation: Using the formula F = G * (m1 * m2) / r^2, we get F = 6.67 x 10^-11 N*m^2/kg^2 * (5 kg * 2.5 x 10^24 kg) / (6.4 x 10^6 m)^2 = 2.01 N.
53 . What is the weight of a 50 kg object on the surface of a planet with a mass of 2.5 x 10^24 kg and a radius of 6.4 x 10^6 m?
A) 122.5 N
B) 245 N
C) 367.5 N
D) 490 N
Answer: A) 122.5 N.
Explanation: The weight of an object is given by the formula W = m * g, where g is the acceleration due to gravity on the surface of the planet. Using the formula g = G * M / r^2, we get g = 6.67 x 10^-11 N*m^2/kg^2 * 2.5 x 10^24 kg / (6.4 x 10^6 m)^2 = 2.53 m/s^2. Substituting into the formula for weight, we get W = 50 kg * 2.53 m/s^2 = 122.5 N.
54 . .Which of the following factors affects the force of gravity between two objects?
A) The distance between the objects
B) The masses of the objects
C) The velocity of the objects
D) All of the above
Answer: D) All of the above.
Explanation: The force of gravity between two objects is determined by the masses of the objects and the distance between them, as given by the formula F = G * (m1 * m2) / r^2, where G is the gravitational constant, m1 and m2 are the masses of the objects, and r is the distance between them. The velocity of the objects does not directly affect the force of gravity, but it can affect the trajectory of the objects if they are in motion relative to each other.
55 . What is the gravitational force between two 1 kg objects that are 1 meter apart?
A) 6.67 x 10^-11 N
B) 6.67 x 10^-10 N
C) 6.67 x 10^-9 N
D) 6.67 x 10^-8 N
Answer: A) 6.67 x 10^-11 N.
Explanation: Using the formula F = G * (m1 * m2) / r^2, we get F = 6.67 x 10^-11 N*m^2/kg^2 * (1 kg * 1 kg) / (1 m)^2 = 6.67 x 10^-11 N.
56 . What is the gravitational force between two 100 kg objects that are 1 meter apart?
A) 6.67 x 10^-7 N
B) 6.67 x 10^-6 N
C) 6.67 x 10^-5 N
D) 6.67 x 10^-4 N
Answer: C) 6.67 x 10^-5 N.
Explanation: Using the formula F = G * (m1 * m2) / r^2, we get F = 6.67 x 10^-11 N*m^2/kg^2 * (100 kg * 100 kg) / (1 m)^2 = 6.67 x 10^-5 N.
57 . If the mass of one of the objects in Question 54 is doubled, what is the new gravitational force between the objects?
A) 1.33 x 10^-4 N
B) 2.67 x 10^-5 N
C) 1.67 x 10^-5 N
D) 3.33 x 10^-5 N
Answer: B) 2.67 x 10^-5 N.
Explanation: Using the formula F = G * (m1 * m2) / r^2, we get F = 6.67 x 10^-11 N*m^2/kg^2 * (200 kg * 100 kg) / (1 m)^2 = 2.67 x 10^-5 N.
58 . What is the acceleration due to gravity on the surface of Mars, where the mass of Mars is 6.39 x 10^23 kg and the radius of Mars is 3,390 km?
A) 2.64 m/s^2
B) 3.71 m/s^2
C) 6.67 m/s^2
D) 9.81 m/s^2
Answer: A) 2.64 m/s^2.
Explanation: The acceleration due to gravity on the surface of a planet is given by the formula g = G * M / r^2, where G is the gravitational constant, M is the mass of the planet, and r is the radius of the planet. Substituting the values given for Mars, we get g = 6.67 x 10^-11 N*m^2/kg^2 * 6.39 x 10^23 kg / (3,390 km * 1000 m/km)^2 = 2.64 m/s^2.
59 . What is the escape velocity from the surface of Earth, where the mass of the Earth is 5.97 x 10^24 kg and the radius of the Earth is 6,371 km?
A) 7.91 km/s
B) 11.2 km/s
C) 15.3 km/s
D) 19.6 km/s
Answer: B) 11.2 km/s.
Explanation: The escape velocity from the surface of a planet is given by the formula v = √(2GM/r), where G is the gravitational constant, M is the mass of the planet, and r is the radius of the planet. Substituting the values given for Earth, we get v = √(2 * 6.67 x 10^-11 N*m^2/kg^2 * 5.97 x 10^24 kg / 6,371 km) = 11.2 km/s.
60 . What is the escape velocity from the surface of a planet with twice the mass and twice the radius of Earth?
A) 11.2 km/s
B) 15.8 km/s
C) 22.4 km/s
D) 31.6 km/s
Answer: D) 31.6 km/s.
Explanation: The escape velocity from the surface of a planet is given by the formula v = √(2GM/r), where G is the gravitational constant, M is the mass of the planet, and r is the radius of the planet. If a planet has twice the mass and twice the radius of Earth, then its mass is 2 * 5.97 x 10^24 kg = 1.19 x 10^25 kg and its radius is 2 * 6,371 km = 12,742 km. Substituting these values into the formula, we get v = √(2 * 6.67 x 10^-11 N*m^2/kg^2 * 1.19 x 10^25 kg / 12,742 km) = 31.6 km/s.