Definitions

Question 1

Define Radian

Answer 1

arc length divided by radius.
to convert from degrees to radians divide by 360 and times by 2pi.

Question 2

define frequency

Answer 2

the number of revolutions per second

Question 3

define period

Answer 3

time taken for a complete revolution

Question 4

derive linear speed equation

Answer 4

linear speed=distance/time therefore 2pi r /T

Question 5

Centripetal acceleration

Answer 5

as velocity for any object moving in a circle is changing, any object moving in a circle is accelerating.

Question 6

angular speed

Answer 6

change of angular displacement with time.
omega= 2pi/ T

Question 7

centripetal force

Answer 7

from newton’s laws, if there’s a centripetal acceleration there must be a centripetal force acting towards the centre of the circle

Question 8

implications of an object moving in a circular path at constant speed

Answer 8

an object is going at a constant speed in a circle doesnt’t have constant velocity as its constantly changing with the direction. since acceleration refers o=to the rate of change of velocity the object is accelerating although the speed is constant.

Question 9

Simple Harmonic Motion

Answer 9

Simple Harmonic Motion is a motion in which the acceleration of the object is always directed towards the equilibrium position, is always in an opposite direction to the displacement, and is always directly proportional to the object’s displacement from the equilibrium position.

a= -kx where x is displacement

Question 10

Conditions of simple harmonic motion

Answer 10

-object oscillates back and forth from either side of equilibrium position
-there’s a restoring-pulling force back towards equilibrium position
-accelleration is always towards equilibrium position
-size of restoring-pulling force is directly proportional to the displacement and negative displacement
-motion of the object is approximately in a straight line

Question 11

examples of objects oscillating in shm

Answer 11

• pendulum
• spring system
• utube

Question 12

free vibrations

Answer 12

NO TRANSFER OF ENERGY FROM OR TO SURROUNDINGS
stretch mass on a spring and it oscillates at its resonant frequency and it will keep oscillating with the same amplitude forever

frequency of applied force= natural frequency

Question 13

forced vibrations

Answer 13

periodic force is applied, frequency is determined by frequency driving force

Question 14

Define damping

Answer 14

The reduction of energy and amplitude of oscillations due to resistive forces on the oscillating system.

Question 15

Light damping

Answer 15

Amplitude doesn’t decrease linearly, it decays exponentially over time.

It’s graph has sinudoisal shape, frequency must remain constant.

Question 16

Critical damping

Answer 16

It returns as quickly as possible to the equilibrium position without oscillating (i.e. car’s suspension system )

Question 17

overdamping

Answer 17

it takes a long time to go back to its equilibrium position without oscillating

Question 18

Define Resonance

Answer 18

When the frequency of the applied force to an oscillating system is equal to its natural frequency, the amplitude of the resulting oscillations increases significantly.

At resonance then system transfers the maximum kinetic energy possible.

Question 19

effects of damping on resonance

Answer 19

Damping reduces amplitude hence affecting the resonance curve (amplitude against frequency)

As damping increases: amplitude decreases so peak lowers, peak broadens
The resonance peak moves slightly to the left of the natural frequency when heavily damped

Question 20

Heavy damping

Answer 20

Amplitude doesn’t decrease linearly, it decays exponentially over time. In a faster rate than light damping.

It’s graph has sinudoisal shape, frequency must remain constant.