Unit 4: Further mechanics Flashcards
What is the equation for momentum
p = mv
where p = momentum, m = mass, v = velocity
What physical law implies total momentum before = total momentum after
Momentum is always conserved in collisions and explosions
What is meant by an elastic collision
Kinetic energy is conserved
e.g. elastic ball bouncing on the floor
What is meant by an inelastic collision
Kinetic energy is not conserved
e.g. Stone falling on the floor
What is the A2 definition Newton’s second law
The net resultant force on an object is equal to the rate of change of its momentum
From the A2 definition of newtons law, derive the standard more commonly know law
- f = (deltamv)/t
- f = mv - mu/t = m((v - u)/t)
- f = m*a
State the equation(s) for an impulse
deltamv = Fdelta*t
What is an impulse
A change in momentum
How does one find the impulse from a force-time graph
The are underneath the graph
What actually is angular velocity
Radians passed through per second
Give the equation for angular velocity
Omega = 2pi/T
Where omega = angular velocity, 2pi = angles in a circle, T = time period to complete a cycle
Give the equation for tangential/ linear velocity in circular motion
v = 2pi*r/T
where r is the radius, 2pi*r = circumference
Combining the equation for angular velocity and tangential velocity gives you:
v = omega*r
