- Who proposed the law of universal gravitation?
A) Galileo
B) Einstein
C) Newton
D) Kepler
- Gravitational force between two masses is always:
A) Repulsive
B) Attractive
C) Zero
D) Random
- The SI unit of gravitational force is:
A) Joule
B) Watt
C) Newton
D) Pascal
- Newton’s law of gravitation is:
F=G m1m2/r2
What does (r) represent?
A) Radius of Earth
B) Distance between centers of masses
C) Radius of orbit only
D) Velocity
- The gravitational constant is represented by:
A) g
B) G
C) F
D) M
- The value of gravitational acceleration near Earth is approximately:
A) 1.6 m/s²
B) 3.7 m/s²
C) 9.8 m/s²
D) 24.8 m/s²
- Weight is measured in:
A) kilograms
B) meters
C) newtons
D) joules
- Mass is measured in:
A) newtons
B) kilograms
C) pascals
D) watts
- Weight depends on:
A) color
B) density only
C) gravity
D) temperature
- Mass remains:
A) variable
B) constant everywhere
C) zero in space
D) dependent on gravity
- If distance between two masses doubles, gravitational force becomes:
A) double
B) half
C) one-fourth
D) four times
- If one mass becomes three times larger, gravitational force becomes:
A) three times larger
B) one-third
C) unchanged
D) nine times larger
- Which law explains planetary motion?
A) Ohm’s law
B) Newton’s law of gravitation
C) Hooke’s law
D) Boyle’s law
- The force keeping planets in orbit is:
A) magnetic force
B) friction
C) gravity
D) tension
- Why do astronauts appear weightless in orbit?
A) No gravity exists there
B) They are beyond Earth’s gravity
C) They are in continuous free fall
D) Space removes mass
- Which scientist experimentally measured G?
A) Einstein
B) Galileo
C) Cavendish
D) Maxwell
- The Moon stays in orbit because gravity provides:
A) frictional force
B) centripetal force
C) magnetic force
D) tension force
- Escape velocity from Earth is approximately:
A) 3 km/s
B) 7.8 km/s
C) 11.2 km/s
D) 25 km/s
- Orbital velocity depends mainly on:
A) object color
B) radius of orbit
C) temperature
D) air resistance only
- Which of the following is NOT affected by gravity?
A) satellite orbit
B) tides
C) planetary motion
D) electric current in wire
- According to Newton’s third law, Earth pulls you with:
A) larger force
B) smaller force
C) equal force
D) zero force
- Gravitational potential energy near a planet is:
PE= – GMm/r
Why is it negative?
A) Energy disappears
B) Gravity is attractive
C) Mass becomes negative
D) Velocity decreases
- General relativity describes gravity as:
A) electric attraction
B) magnetic interaction
C) space-time curvature
D) nuclear force
- Which object has the strongest gravity?
A) asteroid
B) Moon
C) black hole
D) comet
- The inverse-square law means gravitational force decreases rapidly with:
A) mass
B) velocity
C) distance
D) time
- A feather and hammer fall together on the Moon because:
A) there is no gravity
B) mass becomes zero
C) no air resistance exists
D) Moon has no atmosphere and gravity affects both equally
- GPS satellites remain in orbit due to:
A) engine thrust only
B) gravity and forward motion
C) air pressure
D) magnetic attraction
- Tides on Earth are mainly caused by:
A) Earth’s rotation only
B) Moon’s gravity
C) sunlight
D) wind currents
- The Sun’s enormous gravity exists mainly because of its:
A) temperature
B) brightness
C) huge mass
D) magnetic field only
- Which statement is correct?
A) Gravity repels matter
B) Gravity acts only on planets
C) Every object with mass attracts every other object
D) Gravity exists only on Earth
