Scalar: magnitude e.g. mass, energy, speed, distance.
Vector: magnitude and direction e.g. force, velocity, displacement.
F=ma
W=mg
Force (N), m: mass (kg), a: acceleration (m/s2). W: weight (N), g: 9.8 m/s2)
Weight is force due to gravity, so can be different on the moon.
Mass doesn't change but g and weight can.
Resultant force: the sum of all forces acting on an object.
Newton’s 1st Law: if there is a resultant force, an object will accelerate or decelerate. If not, the object will remain stationary or at constant speed.
Newton’s 2nd Law: F=ma
Newton’s 3rd Law: when two objects interact, they exert an equal and opposite force on each other.
Terminal velocity: first, the car would accelerate because the driving force is bigger than the resisting force. Then, the resisting force increases. Eventually, driving force = resistance, so the car will continue at a constant speed.
W=Fs
W: work done (J), s: displacement (m).
F=ke
F: Force (N), k: spring constant (N/m), e: extension (m)
Hooke's Law: extension is directly proportional to the force applied, until the limit of proportionality.
Elastic potential energy: equation given.
M=Fd
M: Moment (Nm), d: distance (m).
Moments are the turning effect of a force.
Displacement is distance travelled in a given direction.
