U1: L3: Day1: Understanding Forces and Motion

What is Newton's First Law of Motion?

• An object will remain in motion only if it is acted upon by a force in the same direction.

• 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 a net external force.

• An object will change its velocity only if it is in motion.

Describe the difference between contact and non-contact forces.

• Contact forces can only occur in a vacuum.

• Contact forces involve direct interaction, whereas non-contact forces operate over a distance.

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

• Non-contact forces require physical touch to act.

How do you represent forces in a force diagram?

• Label each force with a number instead of using arrows.

• Draw arrows for each force, with length indicating magnitude and direction shown by the arrowhead.

• Use circles to represent forces without indicating direction.

• Draw lines connecting forces without showing their magnitude.

What is the formula for calculating frictional force?

• F_friction = N - μ

• F_friction = μ * N

• F_friction = μ + N

• F_friction = N / μ

Explain Newton's Second Law of Motion with an example.

• Newton's Second Law of Motion explains that force equals mass times acceleration (F = ma), illustrated by a 10 kg object accelerating at 2 m/s² when pushed with 20 N.

• Force is equal to mass divided by acceleration (F = m/a)

• A 5 kg object remains stationary when a 10 N force is applied

• Acceleration is independent of mass and force

What are the different types of friction and how do they affect motion?

• Friction is only present in solid materials.

• The different types of friction are static friction, kinetic friction, rolling friction, and fluid friction, each affecting motion by opposing or allowing movement.

• There are only two types of friction: static and dynamic.

• Friction always increases the speed of an object.

How does Newton's Third Law of Motion apply to everyday situations?

• Sitting in a chair creates no reaction force against the ground.

• Newton's Third Law of Motion applies to everyday situations by demonstrating that every action has an equal and opposite reaction, such as sitting in a chair or walking.

• Newton's Third Law only applies to objects in motion, not at rest.

• Every action results in a greater force acting in the same direction.

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

• Mass has no effect on force or motion.

• More mass always means more speed.

• Mass is irrelevant to the amount of force applied.

• Mass determines the amount of force needed to change an object's motion.