Forces
What is the definition of a force?
A force is a push or pull that can change the motion or shape of an object. It is a vector quantity, meaning it has both magnitude and direction.
How is energy related to work?
Energy is the capacity to do work. When work is done on an object, its energy is increased or decreased depending on the direction of the work done.
Can an object continue to move in a straight line at a constant speed without force? Why?
No because an object at rest will stay at rest, and an object in motion will stay in motion with a constant velocity, unless acted upon by an external force.
What are the SI units of impulse?
The SI units of impulse are Newton seconds or kilogram meter per second.
What is momentum?
Momentum is the product of an object's mass and its velocity. It is a vector quantity, meaning it has both magnitude and direction.
What are the two main types of forces?
The two main types of forces are contact forces and non contact forces.
How is power related to work and time?
Power is equal to the work done divided by the time taken to do that work. Mathematically, power = work/time.
Why is the first law of motion also called the law of inertia?
The first law of motion is often referred to as the law of inertia because it describes how objects tend to maintain their state of motion or rest.
What is impulse in physics?
Impulse is defined as the change in momentum of an object.
What is the principle of conservation of momentum?
The principle of conservation of momentum states that the total momentum of a closed system remains constant if no external forces act on it.
What is the difference between balanced and unbalanced forces?
Balanced forces are forces that are equal in magnitude and opposite in direction, resulting in no change in the object's motion.
An unbalanced force will cause an object to accelerate, decelerate, or change direction.
Transfer of energy that occurs when a force is applied over a distance and acts in the direction of the force.
What is work?
What is Newton's First Law of Motion?
An object at rest will stay at rest, and an object in motion will stay in uniform motion in a straight line unless acted upon by an external force.
How is impulse calculated?
Impulse is calculated by multiplying the force applied to an object by the time interval during which the force is applied. The formula for impulse is impulse = force × time.
Does the conservation of momentum apply to all types of collisions?
Yes.
What is the net force of a mass, 20kg sliding down an inclined plane at an angle of 30 degrees, given that a frictional force of 40 N acts up the slope?
mgsin30 - Fr
20x9.81sin30 - 40
=58.1 N
What is the conservation of energy principle in physics?
The conservation of energy principle states that energy cannot be created or destroyed, but it can only be transferred or transformed from one form to another.
Does Newtons Second Law have any kind of relationship with acceleration, and what kind?
Acceleration and force have a linear relationship, meaning that increasing the force applied to an object will directly increase its acceleration.
How can impulse affect an object's motion?
When a force is applied over a longer time interval, the change in momentum and velocity of an object will be smaller.
When does the conservation of momentum apply?
The conservation of momentum applies in situations where no external forces are acting on the system, or if the external forces can be neglected compared to the internal forces within the system.
What is the Newton's Third Law pair force to the force of gravity experience by a book resting on a table?
The force of the book pulling upwards on the Earth.
Can work be negative? Explain in full.
A negative value of work indicates that the force applied is in the opposite direction of the object's displacement, meaning work is done against the motion of the object.
How is the conservation of momentum related to Newton's third law of motion?
The conservation of momentum is related to Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. When objects interact with each other, their momenta change, but the total momentum of the system remains constant.
What happens to the impulse on an object in a collision?
The impulse on an object is equal to the change in momentum of the object. If there is no external force acting on the system, the impulse on each object involved in the collision will be equal in magnitude but opposite in direction.
One cart of mass 300 kg travels east at 5 m/s. It hits a cart of 200 kg travelling in the opposite direction at 8 m/s/ If the 300 kg cart has a final velocity of 2 m/s, what is the final velocity of the 700 kg cart?
m1u1 +m2u2 = m1v1 +m2v2
1500 -1600 = 600 + 700 v
-700= 700 v
v =-1 m/s