Chap 3 Forces Flashcards
What is a force?
A force is a push or pull that one object exerts on another.
What are the 5 grand types of forces?
Gravitational force, Magnetic Force, Electric Force, Nuclear strong force, Nuclear weak force.
What is the Si unit of force?
The SI unit of force is newton (N). A force of 1N is roughly the amount of force the Earth’s gravity pulls on a 100g mass.
What are all the scalar quantities?
Distance, speed, energy, time, volume, density and power.
What are all the vector quantities?
Displacement, velocity, force and acceleration.
What is the effect of a force on motion?
A force can cause a stationary object to start moving
A force can cause a moving object to increase speed
A force can cause a moving object to decrease speed
A force can cause a moving object to change its direction
What does an object having zero acceleration imply?
An object having zero acceleration implies that the object could be stationary or moving with constant velocity.
Define newton’s first law of motion?
Every object will continue in its state of rest or uniform motion in a straight line unless a resultant force acts on it.
What happens when the forces acting on the an object are unbalanced.
The unbalanced forces causes an object to accelerate, decelerate or change direction. The direction of acceleration is in the direction of the resultant force.
Define Newton’s Second Law of motion?
When a resultant force acts on an object of a constant mass, the object will accelerate in the direction of the resultant force, The product of the mass and acceleration of the object gives the resultant force.
Define weight
Weight is an ever-present force exerted on every object due to gravity.
Define Newton’s Third Law of motion
For every action, there is an equal and opposite reaction and these forces act on mutually opposite bodies.
What are the 4 characteristics of Newton’s Third Law of motion.
Forces always occurs in pairs
Action and reaction forces are equal in magnitude
Action and reaction forces act in opposite directions
Action and reaction forces act on different bodies
How does friction affect motion?
Friction always opposes motion between two surfaces in contact.
What are the negative and positive effects of friction?
One negative effect of friction is that it causes wear and tear of moving parts in machinery. One positive impact of friction is that it increases grip.
