Understanding Gravity and Friction

What is Newton's Law of Gravitation?

• Every mass repels every other mass with a force proportional to the sum of their masses.

• Only large masses attract each other with a constant force.

• Gravitation is only applicable to celestial bodies and not to objects on Earth.

• Every mass attracts every other mass with a force proportional to the product of their masses and inversely proportional to the square of the distance between them.

How does gravity affect the weight of an object?

• Gravity only affects objects in motion.

• Gravity has no effect on weight.

• Weight is solely determined by an object's mass.

• Gravity affects the weight of an object by determining the gravitational force acting on it.

What happens to objects in free fall due to gravity?

• Objects in free fall accelerate towards the ground due to gravity.

• Objects in free fall float away from the ground.

• Objects in free fall remain stationary in the air.

• Objects in free fall are pushed upwards by gravity.

Can gravity act at a distance?

• Yes, gravity can act at a distance.

• Gravity only acts on objects in contact.

• Gravity cannot influence objects in space.

• Gravity is only a force on Earth.

Which of the following is a desirable effect of a friction?

• Making gears rusty

• Friction creates slippery roads

• Friction makes moving objects easy

• Friction creates grip for vehicle tires

What is the effect of gravity on the motion of planets?

• Gravity has no effect on planetary motion.

• Planets move in straight lines due to gravity.

• Gravity causes planets to orbit stars in elliptical paths.

• Gravity causes planets to collide with each other.

What are the two main types of friction?

• Static friction and kinetic friction

• Air friction and gravitational friction

• Fluid friction and surface friction

• Sliding friction and rolling friction

Can you give an example of static friction?

• A ball rolling down a hill.

• A car sliding on ice.

• A book resting on a table.

• A person pushing a heavy box across the floor.

What is kinetic friction?

• Kinetic friction is the frictional force acting between moving surfaces.

• Kinetic friction is the force that prevents motion between stationary surfaces.

• Kinetic friction only occurs in liquids and gases.

• Kinetic friction is the force that increases with the speed of the moving object.

How does friction affect the speed of a sliding object?

• Friction increases the speed of a sliding object.

• Friction has no effect on the speed of a sliding object.

• Friction only affects the direction of a sliding object.

• Friction decreases the speed of a sliding object.