Newton's law of gravitation and field strength

Question 1

Who first published the law of universal gravitation?

• A. Albert Einstein
• B. Johannes Kepler
• C. Isaac Newton
• D. Galileo Galilei

Question 2

Calculate the gravitational field strength at the surface of Earth, in N/kg. Mass = 5.97 × 10²⁴ kg, radius = 6.37 × 10⁶ m, G = 6.67 × 10⁻¹¹ N m²/kg². (g = G M ÷ r²; give 1 decimal place)

Answer N/kg

Question 3

The distance between two masses is multiplied by 2. By what factor does the gravitational force between them change? (F = G m₁ m₂ ÷ r²; give 4 decimal places if needed)

Answer 

Question 4

Who first published the law of universal gravitation?

• A. Isaac Newton
• B. Albert Einstein
• C. Johannes Kepler
• D. Galileo Galilei

Question 5

Calculate the gravitational field strength at the surface of Earth, in N/kg. Mass = 5.97 × 10²⁴ kg, radius = 6.37 × 10⁶ m, G = 6.67 × 10⁻¹¹ N m²/kg². (g = G M ÷ r²; give 1 decimal place)

Answer N/kg

Question 6

The distance between two masses is multiplied by 3. By what factor does the gravitational force between them change? (F = G m₁ m₂ ÷ r²; give 4 decimal places if needed)

Answer 

Question 7

Why is the value of g slightly smaller at the top of a high mountain?

• A. It is colder
• B. You are slightly further from Earth's centre
• C. There is less air
• D. Mountains have less mass

Question 8

Calculate the gravitational field strength at the surface of Jupiter, in N/kg. Mass = 1.9 × 10²⁷ kg, radius = 6.99 × 10⁷ m, G = 6.67 × 10⁻¹¹ N m²/kg². (g = G M ÷ r²; give 1 decimal place)

Answer N/kg

Question 9

One of two masses is multiplied by 0.5 and the distance stays the same. By what factor does the gravitational force change? (F = G m₁ m₂ ÷ r²)

Answer 

Question 10

Who first published the law of universal gravitation?

• A. Galileo Galilei
• B. Albert Einstein
• C. Isaac Newton
• D. Johannes Kepler

Question 11

Calculate the gravitational field strength at the surface of Mars, in N/kg. Mass = 6.42 × 10²³ kg, radius = 3.39 × 10⁶ m, G = 6.67 × 10⁻¹¹ N m²/kg². (g = G M ÷ r²; give 1 decimal place)

Answer N/kg

Question 12

The distance between two masses is multiplied by 0.5. By what factor does the gravitational force between them change? (F = G m₁ m₂ ÷ r²; give 4 decimal places if needed)

Answer 

Question 13

Why is the value of g slightly smaller at the top of a high mountain?

• A. It is colder
• B. Mountains have less mass
• C. There is less air
• D. You are slightly further from Earth's centre

Question 14

Calculate the gravitational field strength at the surface of Earth, in N/kg. Mass = 5.97 × 10²⁴ kg, radius = 6.37 × 10⁶ m, G = 6.67 × 10⁻¹¹ N m²/kg². (g = G M ÷ r²; give 1 decimal place)

Answer N/kg

Question 15

One of two masses is multiplied by 2 and the distance stays the same. By what factor does the gravitational force change? (F = G m₁ m₂ ÷ r²)

Answer 

Question 16

Why do all objects near Earth's surface fall with the same acceleration (ignoring air)?

• A. Light objects are pulled harder
• B. Heavier objects feel no extra force
• C. A larger mass feels a larger force, but also needs more force to accelerate, so a = g for all
• D. Gravity does not depend on mass