Part X Flashcards
AP1.1.A What are scalars?
Quantities that are described by a magnitude alone.
Examples include: speed, mass and distance
AP1.1.A What are vectors?
Quantities that are described by a magnitude and direction.
Examples include: velocity, momentum, force, weight, acceleration and displacement
AP1.1B Know and be able to interpret vector notation
AP1.2.AB How do you resolve a vector into two components at right angles to each other or find the resultant of two vectors at any angles to each other?
By drawing or by using trigonometry.
By drawing or by using trigonometry to split the components into perpendicular forces and Pythagoras’s theorem.
AP1.3.A What is a moment defined as?
Force × perpendicular distance from the point to the line of action of the force.
AP1.3.B Be able to calculate the moment of a force about a point
AP1.3.C What is the principle of moments?
When a body is in equilibrium, the total clockwise moment about a point equals the total anticlockwise moment about the same point.
AP1.4 What are the contact forces?
The normal force which is perpendicular to the surface.
The friction force which opposes the direction of motion.
AP1.5 What conditions are needed for a particle to be in equilibrium?
When the resultant of all forces acting on the particle is zero.
AP1.6 What does smooth and rough mean?
Smooth: friction does not need to be taken into account.
Rough: friction does need to be taken into account.
AP1.7.AB What is the centre of gravity?
The point at which the weight of a body acts through.
This is along the line of symmetry on symmetrical bodies.
AP1.8.A Solve problems involving equilibrium of rigid bodies under coplanar forces (zero resultant force and zero resultant moment):
a. These problems could involve an object on an inclined plane, with or without friction.
AP1.8.B Understand and apply the representation of forces using a triangle of forces.
AP2.1 Understand graphical methods involving distance, displacement, speed, velocity, acceleration and time.
AP2.2 Use graphical representation of 1-dimensional motion to make various deductions (for example, find the displacement from a velocity–time graph).
AP2.3 What are the suvat equations?
v=u+at
s = ut + 1/2at^2
s=((u+v)t)/2
v^2 =u^2 +2as
AP2.4 What is the equation linking velocity, power and force?
power = force × velocity
AP3.1 What are Newton’s laws?
1: A body will remain at rest or at a constant velocity unless acted on by a resultant force.
2: F=ma.
3: Every action has an equal and opposite reaction.
AP3.1 How is terminal velocity reached?
Initially, the only force acting on the object is it’s weight so it’s velocity increases. As it accelerates, they impact with the particles in the air. Due to Newton’s third law this means the particles will have an increasing upwards force on the object. This is air resistance. As velocity and air resistance increase, due to Newton’s second law, the resultant force and rate of acceleration decreases. When weight is equal to drag, the resultant force is zero so the object has reached a maximum and constant velocity.
AP3.2 Model a body moving vertically, or on an inclined plane, with constant acceleration.
AP3.3.A What forces are acting in projectile motion?
No forces in the horizontal direction.
Weight in the vertical direction.
AP3.3.B What are the effects on air resistance on projectile motion?
The air resistance lowers the speed of an object in trajectory. Due to this, the time an object takes to reach the ground is increased. It is also responsible for changing the trajectory path of the object.