Mechanics Flashcards
(31 cards)
What are the equations of motion? (5)
v = u + at s = ut + 1/2at^2 s = vt - 1/2at^2 v^2 = u^2 + 2as s = (u + v)t/2
What is the acceleration due to gravity?
9.8ms^-2
On a displacement-time graph what does each line mean? Curved Straight inclined Horizontal Straight inclined in other direction
Acceleration
Constant velocity
Stationary
Constant velocity in other direction
On a velocity-time graph what does each line mean? Curved Straight incline Horizontal Straight inclined in other direction
Non-uniform acceleration
Uniform acceleration
Constant velocity
Uniform deceleration
How do you resolve horizontally?
ucosx
How do you resolve vertically?
usinx
What component remains constant in a projectiles question?
Horizontal, neglecting air resistance
How do you solve a projectiles question? (3)
Resolve horizontally and vertically
Use the vertical component to work out how long its in the air and how high it goes
Use the horizontal component to work out how far it goes whilst in the air
State Newton’s first law
An object will remain in its current state of motion unless acted upon by a resultant force
When is a body said to be in equilibrium?
When a number of forces act on a body the vector sum equals zero
What is the centre of mass?
The point at which all the mass is concentrated
State Newton’s second law
F=ma
State Newton’s third law
If body A exerts a force on body B, the body B will exert a force on body A
What are the similarities of Newton’s third law pairs? (4)
Type
Act along the same line
Act for the same time
Equal magnitude
What are the differences of Newton’s third law pairs? (2)
Act on different bodies
Act in opposite directions
What is the relationship between work and energy?
Energy is transferred when work is done on it
What is the principle of conservation of energy?
Energy cannot be created or destroyed. It can be transferred into other forms
KE=GPE=WD=EPE
What is power?
The rate of doing work
What is the centre of gravity?
The point at which the weight of a body may be considered to act
What is meant by work done?
Force x distance moved in the direction of the applied force
When a ball is thrown vertically upwards, at the maximum height what is the acceleration of the ball?
-9.8ms^-1
Why is it necessary that the maximum mass is not exceeded on a spring? (3)
The elastic limit will be exceeded
The spring will not return to its original dimension
The spring constant will change
Describe the energy transfers of a bungee jumper
GPE -> KE
GPE + KE -> EPE
EPE -> KE + GPE
Is force a vector or scalar?
Vector
