Mechanics - Force and Momentum Flashcards
Force
Anything that makes an object move or change velocity.
The acceleration of a body is ‘x’ to the force acting on it.
proportional
‘An object’s mass is related -‘
‘to how difficult it is to move the object or change its velocity.’
What happens if the force is kept constant?
The mass it acts on is changed, the acceleration is inversely proportional to the mass.
Momentum
The momentum of a body is the product of its mass and velocity. *How difficult it is to move something!
What is the equation for momentum?
p=mv, where p is momentum, m is mass and v is velocity.
What is the equation for force?
F=kma, where k is a constant
State Newton’s 1st Law of Motion
All bodies will remain at rest or travelling at a constant velocity unless acted upon by an unbalanced external force.
State Newton’s 2nd Law of Motion
When an unbalanced force acts on a body, the rate of change of momentum is proportional to the force and takes place in the direction of that force.
State Newton’s 3rd Law of Motion
If body A puts a force onto body B, body B puts an equal but opposite force onto body A.
Define Newton’s Law of Universal Gravitation
Every mass in the universe attracts every other mass with a force, along the lines of their centres, that is proportional to the product of their masses and inversely proportional to the square of the distance between them.
Express the equation for universal gravitation
F = Gm1 m2/ d^2
What is the distance in terms of the universal gravitation?
The distance from radius to radius.
Define gravity
Attractive force exerted by any mass on any other mass.
Is gravity a strong force of weak force?
It’s a very weak force, when mass exerting force is large.
