P2 Flashcards
What is acceleration? Give the formula.
Acceleration = change in velocity ÷ time
It is the rate of change of velocity. It is a vector (directional) quantity.
Calculate the kinetic energy, in joules, of a ball of mass 0.5kg moving at 16m/s^2.
Kinetic energy = 0.5 × mass × velocity^2.
0.5 × 0.5 × 16^2 = 64 J
What is net force?
The overall force or conbination of forces acting on an object.
What is Newton’s First Law?
Law of Inertia - An object will remain stationary or will continue moving at a constant velocity unless an external force is applied.
What is Newton’s Second Law?
Acceleration is bigger when the force is bigger, but smaller when the mass is bigger.
A.K.A:
Force = mass × acceleration.
What is Newton’s Third Law?
Every force has an equal and opposite reaction force/resultant force.
Why is more force required to move a heavier object?
Objects with higher masses have more inertia, meaning it is more difficult to change its velocity and a greater force is needed to produce an acceleration.
What is terminal velocity?
When an object is falling, air resistance acts as an opposite, resistive force is response to the force of gravity pulling th object down. The resistive force begins as something small, allowing the object to accelerate, but as the object continues to fall eventually the resistive force will increase to be the same size as the force of weight, meaning that now the object will fall at a constant velocity - the terminal velocity.
What kind of quantity is momentum? What is it?
It is a vector quantity, and it is the product of mass and velocity.
Give the formula for momentum.
Momentum = velocity × mass
What happens to monentum during a collision?
The monentum is conserved, so the total momentum before = the total momentum after.
Give the formula for work done.
work done (J) = force × distance
Give the unit for momentum.
kgm/s
Define power.
The rate of transfer of energy.
Give the unit for power.
Watts (W)
