Further Mechanics

Question 1

Define Simple Harmonic Motion

Answer 1

Oscillation where acceleration is directly proportional to its negative displacement

Question 2

Which way is acceleration directed

Answer 2

Always towards the equilibrium

Question 3

Define Forced Vibrations

Answer 3

When periodic force is applied the frequency is determined by the frequency of the driving force

Question 4

Resonance

Answer 4

Occurs when the frequency of applied force= natural frequency, it produces vibrations of large amplitude as maximum energy is transferred

Question 5

Damping

Answer 5

When force opposes the motion and removes energy

Question 6

Free Vibration

Answer 6

System displaced and left to oscillate

Question 7

How does damping affect the resonance

Answer 7

Reduces sharpness of resonance and reduces amplitude at the resonant frequency

Question 8

For a mass-spring what is the resultant force acting on the mass composed of

Answer 8

Composed of its weight and the tension in the spring system

Question 9

Where is velocity greatest

Answer 9

At the equilibrium where x=0

Question 10

Where is acceleration greatest

Answer 10

When x is greatest therefore when x=A

Question 11

Which way does damping act

Answer 11

Opposite direction to velocity

Question 12

Name 3 types of damping

Answer 12

Lightly damped, Heavily damped and Critical

Question 13

What are the 2 types of potential energy involved in a mass-spring system

Answer 13

gravitational Potential and Elastic Potential

Question 14

Define Angular Speed

Answer 14

The angle turned per unit time, measured in rads-1

Question 15

Define Radian

Answer 15

The angle subtended at the centre of the circle by an arc that is equal in length to the radius

Question 16

Why is car driving round a roundabout at constant speed accelerating

Answer 16

• Because velocity is a vector, and because its direction is constantly changing , its velocity is always changing, therefore it must have acceleration
• Newtons first law states that an object remains at rest or continues at constant velocity unless acted on by a resultant force. This means that because it has a force acting towards the centre of the circle

Question 17

Which way is centripetal acceleration always directed

Answer 17

Towards the centre of the circle

Question 18

What is centripetal force

Answer 18

It is the name given to the resultant force acting towards the centre of the circle, it itself is not a physical force

Question 19

In a pendulum what is the centripetal force provided by

Answer 19

The horizontal component of tension

Question 20

For a car on a banked track what contributes to the centripetal force

Answer 20

Horizontal Component of normal reaction force and lateral friction

Question 21

When is the velocity of a pendulum in SHM greatest

Answer 21

When the pendulum is at its equilibrium

Question 22

When is the acceleration of a pendulum in SHM greatest

Answer 22

When the magnitude is greatest

Question 23

What is the only way to alter the time period of a pendulum

Answer 23

Alter the length

Question 24

What is the total energy of a free oscillation, and how does it change

Answer 24

Sum of the potential energy and kinetic energy, and is constant throughout the oscillation