Forces in Action
What is the definition of a force?
A push or a pull acting on an object that can cause it to accelerate.
What is another name for Newton's First Law?
The Law of Inertia.
How does friction change on rough versus smooth surfaces?
Friction is greater on rough surfaces, making it harder to move objects.
A force of 500N is applied to a 100kg object. What is its acceleration?
a = F/m
5 m/s2 = 500/100
What happens when you push a wall, according to Newton's Third Law?
The wall pushes back with an equal and opposite force.
What is the difference between weight and mass. How does gravity affect each one?
Mass is the amount of matter in an object and doesn’t change with gravity.
Weight is the force exerted by gravity on an object and depends on both mass and the strength of gravity.
What are the two general types of forces?
Contact forces and non-contact forces.
According to Newton's First Law, what happens to an object at rest or in motion?
It stays at rest or in motion unless acted on by an unbalanced force.
What is the difference between static and kinetic friction?
Static friction prevents an object from moving, while kinetic friction opposes motion once the object is moving.
If a 10 kg object is accelerated at 2 m/s2 what is the force applied?
F = m x a
10 x 2 = 20 N
How does a rocket launch according to Newton's Third Law?
The rocket pushes gases downward (action). and the gases push the rocket upward (reaction).
What is tension force in physics?
A pulling force exerted by a rope, string, or other object.
What is the formula for Newton's Second Law?
Force = mass x acceleration
Why do objects of different masses fall at the same rate in the absence of air resistance?
Because gravity acts equally on all objects, regardless of their mass.
A car has a mass of 500 kg. A force of 1,000 N is applied. What is the car's acceleration?
a = F/m
1000/500 = 2 m/s2
How des Newton's First Law explain why a book stays on a table until you push it?
An object at rest stays at rest uless acted upon by an unbalanced force.
What is the normal force?
The support force exerted by a surface perpendicular to the object.
Describe an example of Newton's Third Law in everyday life, describe the action and reaction force.
ex: When you jump off a boat, your feet push the boad backward (action), and the boat pushes you forward (reaction).
What is the value of gravitational acceleration on Earth? (gravitational constant on Earth)
9.8 m/s2
What happens to the acceleration of an object if the force stays the same but the mass is doubled?
The acceleration is cut in half.
How does increasing a car's mass affect the force needed to stop it?
More force is needed because force is proportional to mass.
What is magnetic force, and how does it act between materials?
Magnetic force is the attraction or repulsion between magnetic materials.
How does increasing the force on an object affect its acceleration, assuming mass remains constant?
The object's acceleration increases.
What is the difference between static and kinetic friction?
Friction is a force that opposes motion between two surfaces in contact.
A 2,000 N force is applied to a car, and it accelerates at 4 m/s2. What is the car's mass?
m = F/a
500 kg = 2000/4
Explain how a basketball player jumping and landing demonstrates Newton's Third Law?
The player pushes down on the ground (action), and the ground pushes the player up (reaction).