3.6.1 Further Mechanics

Question 1

angular displacement

Answer 1

the angle an object in circular motion turns through

Question 2

angular speed

Answer 2

the rate of change of angular displacement of an object in circular motion rads^-1

Question 3

centripetal force

Answer 3

the resultant force that acts on an object that moves along a circular path

Question 4

damped oscillations

Answer 4

Oscillations that reduce in amplitude due to presence of resistive forces like friction or drag

Question 5

principle of conservation of momentum

Answer 5

when 2 or more bodies interact - total momentum is unchanged provided no external forces act on the bodies

Question 6

resonance

Answer 6

• Resonance occurs when the frequency of oscillations is equal to the natural frequency of the oscillating system.
• The rate of energy transfer is at a maximum during resonance

Question 7

simple harmonic motion

Answer 7

motion of an object if its acceleration is proportional to the displacement of the object from equilibrium and is always directed towards the equilibrium position

Question 8

time period

Answer 8

time taken for one complete cycle of oscillations

Question 9

uniform circular motion

Answer 9

motion of an object moving at a constant speed along a circular path

Question 10

radian

Answer 10

1 rad = 360° or 2π

Question 11

satellite

Answer 11

small object in orbit round a larger object

Question 12

satellite motion

Answer 12

satellite moving around a planet: substitute V^2/r into V = 2π/T and equating g = Gm/r^2 will give T^2 = ( 4π^2/Gm)r^3

Question 13

orbital period for satellites

Answer 13

T^2 proportional to r^3

Question 14

forced vibrations

Answer 14

vibrations

Question 15

free vibrations

Answer 15

oscillations where there is no damping and no periodic force acting on the system, so the amplitude of the oscillations is constant

Question 16

periodic force

Answer 16

force that varies regularly in magnitude with a definite time period

Question 17

phase difference

Answer 17

for 2 objects oscillating with the same time period - time difference between successive instants when the 2 objects are at maximum displacement in the same direction