GRAVITY

The force attraction between two objects of masses “M“ and “m” which lie at a distance “d” from each other is directly proportional to the _____.

• sum of the masses of objects M+m

• product of the masses of objects M×m

• difference between masses of objects M-m

• sum of the squares of masses of objects M²+m²

Which of the phenomenon mentioned in the options is NOT explained by the universal law of gravitaton?

• The motion of the moon around the earth.

• The tides are due to the moon and the sun.

• The force that binds us to the earth.

• The motion of sun around the planets.

Every particle in the universe attracts every other particle with a force that is proportional to ______ and inversely proportional to ______ between them.

• the sum of their masses; the square of the distance

• the square of the distance; the product of their masses

• the product of their masses; the distance

• the product of their masses; the square of the distance

Which of the following statements bout gravitational force is NOT correct?

• It is experienced by all bodies in the universe.

• It is a dominant force between celestial bodies

• It is a negligible force for atoms.

• It is the same for all pairs of bodies in our universe.

The Copernicus’s model does NOT solve which of the following?

• The different brightness of the planets is due to the fact that they are different distances from Earth.

• The retrograde motion could be explained in terms of geometry and a faster motion for planets with smaller orbits.

• The stars to appear to revolve around the Earth once in 24h.

• It can explain all the details of planetary motion on the celestial sphere without epicycles.

What is NOT correct in the Copernicus’s model?

• Earth/planets orbit the Sun in circular orbits.

• The Moon is in orbit around the Earth.

• The stars orbit the Sun.

• The Earth rotate once in 24 hours

How does the gravitational attraction between two point masses change if the distance is doubled and the mass of each object is halved?

• 4 times more

• 16 times more

• 4 times less

• 16 times less

How many times does the gravitational attraction between two point masses increase if the distance is 4 times increased and the mass of one object is tripled?

• 3/16 times

• 3/4 times

• 4 times

• 3 times

How many times does the gravitational attraction between two point masses increase if the distance is 2 times increased and the mass of one object is tripled?

• 3/16 times

• 3/4 times

• 3/2 times

• 3 times

Compared to the Earth, Planet X has twice the mass and twice the radius. This means that compared to the Earth’s surface gravity, the surface gravity on Planet X is

• 4 times as much.

• twice as much.

• the same.

• 1/2 as much.