Understanding Forces in Physics

What is Newton's First Law of Motion?

• An object in motion will eventually stop without any force acting on it.

• An object will accelerate if no forces are acting on it.

• An object will remain at rest or in uniform motion unless acted upon by an external force.

• An object will change direction only if a force is applied.

State Newton's Second Law of Motion and its formula.

• F = m/a

• F = mv

• F = ma

• F = m + a

What does Newton's Third Law of Motion state?

• For every action, there is a proportional reaction.

• An object at rest stays at rest unless acted upon by a force.

• The force of an object is equal to its mass times its velocity.

• For every action, there is an equal and opposite reaction.

What are the four fundamental forces in nature?

• Gravitational force, electromagnetic force, strong nuclear force, weak nuclear force

• Magnetic force

• Centrifugal force

• Frictional force

Define gravitational force and give an example.

• The force that pushes objects away from each other, like magnets.

• The attraction between two objects that is only felt in space.

• The force that causes a ball to roll uphill against gravity.

• An example of gravitational force is the attraction between the Earth and an apple, which causes the apple to fall to the ground.

What is the difference between contact and non-contact forces?

• Contact forces are always stronger than non-contact forces.

• Non-contact forces require physical touch to act.

• Contact forces can only be observed in liquids.

• Contact forces involve direct interaction; non-contact forces operate at a distance.

How does force affect the acceleration of an object?

• Force only affects the speed, not the acceleration of an object.

• Force affects the acceleration of an object by increasing it proportionally.

• Force decreases the acceleration of an object.

• Force has no effect on the acceleration of an object.

If a 10 kg object experiences a force of 20 N, what is its acceleration?

• 1 m/s²

• 4 m/s²

• 10 m/s²

• 2 m/s²

Explain how frictional force acts on moving objects.

• Frictional force opposes the motion of moving objects, slowing them down due to surface interactions.

• Frictional force accelerates moving objects, increasing their speed.

• Frictional force has no effect on the motion of objects.

• Frictional force only acts on stationary objects, not on moving ones.

What role does mass play in the relationship between force and acceleration?

• Mass inversely affects acceleration; greater mass results in less acceleration for a given force.

• Mass has no effect on acceleration.

• Force is independent of mass in determining acceleration.

• Greater mass always results in greater acceleration.