further mechanics (simple harmonic motion)

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How do you convert from radians to degrees?

degrees x pi/180

linear speed is…

distance that an object travels in a straight line per second

angular speed is…

angle that an object rotates through per second

frequency

number of complete revolutions/cycles per second

what does the centripetal force do?

it acts towards the centre of a circle, causing the object to undergo circular motion

what provides the centripetal force for a toy swung in a circle on a string?

tension in the string

what provides the centripetal force for a satellite orbitting the earth?

gravitational force

why can a car travel at higher speeds on a banked slope than on a horizontal circular track?

the normal force has a component towards the centre of the circle, so less friction required to remain at the same height on the slope. the car can travel at higher speeds before reaching the frictional limit of the tyres.

amplitude

maximum displacement of the object from its equilibrium

time period

time taken for one complete cycle of oscillation

phase difference

measure of how much one wave lags behind another- measured in degrees/radians/fractions of a cycle

simple harmonic motion

an oscillation in which the acceleration of an object is directly proportional to its displacement from its equilibrium position, and is directed towards the equilibrium.

how do you find velocity from a displacement-time graph?

gradient

how do you find acceleration from a velocity-time graph?

gradient

where is the maximum speed for a simple pendulum?

at the equilibrium point

where is the maximum potential energy for a simple pendulum?

at maximum displacement

where is the maximum kinetic energy for a simple pendulum?

at the equilibrium point

what is the angular speed of the earth orbiting the sun in radsec-1

2×10^-7 radsec-1

what are free vibrations?

involve no transfer of energy to or from the surroundings

what are forced vibrations?

vibrations that occur when an external driving force is moving periodically

what is the phase difference of the driver and the oscillator when resonance is achieved?

90 degrees

what is damping?

an oscillating system losing energy to its surroundings due to friction/air resistance

what is light damping?

takes a long time to stop oscillating. amplitude reduces by small amount each cycle

what is heavy damping?

strong resistive forces prevent oscillation, causing it to return slowly and smoothly to equilibrium without overshooting

what is critical damping?

reduces the amplitude to zero in the shortest time possible