our dynamic universe pt.1 Flashcards
acceleration
the change in velocity per unit time
acceleration units
ms^-2
newtons 1st law
an object will remain at rest, or continue with a constant velocity in a straight line, unless acted upon by an unbalanced force
newtons 2nd law
F=ma
resolving vectors mnemonic
CHAVS (cos horizontal and vertical sin)
Vv
vsinx
Vh
vcosx
law of the conservation of energy
energy cannot be created or destroyed, just changed from one form to another
tension when the object is moving at a constant speed (acceleration is 0)
zero
constant speed in terms of forces
balanced forces
force on a slope equation
F=mgsinx
momentum units
kgms^-1
law of the conservation of momentum
the total momentum before is equal to the total momentum after, in the absence of external forces
total energy in a collision
total energy is always conserved
kinetic energy in a collision
kinetic energy is only conserved in an elastic collision, not in an inelastic collision
impulse
the change in momentum
impulse units
kgms^-1 or Ns
impulse, vector or scalar
vector
energy, vector or scalar
scalar
another way to calculate impulse
the area under a force-time graph
converting ms to s
divide it by 1000
explain why the tension in each rope increases when an angle is added
tension now has a horizontal component, vertical component of tension is unchanged
improving reliability of an experiment
repeat measurements, use additional (gratings)
a cable breaks when a drone hovers at a constant height, describe the vertical motion
accelerates upwards as upwards force is greater than weight
explain in terms of forces why a terminal velocity may be reached
frictional force increases and this and the weight become balanced
