Mechanics-Linear Definitions I

Question 1

Displacement is: {Definition}

Answer 1

Displacement is distance from a point in a given direction. [m]

Question 2

Velocity is: {Formula}

Answer 2

Velocity is:
displacement/time [m/s].
V = s/t [V=final velocity, s=displacement, t=time]

Question 3

Acceleration is: {Formula}

Answer 3

Acceleration is:
change in velocity/time [m/s2]
a = (v – u)/t [a=acceleration, v=final velocity, u=initial velocity, t=time]

Question 4

A vector is: {Definition}

Answer 4

A vector is a quantity with magnitude and direction. E.g., force, acceleration.

Question 5

A scalar is: {Definition}

Answer 5

A scalar is a quantity with magnitude only. E.g., distance, time, mass.

Question 6

Newton’s 1st law of motion: {Definition}

Answer 6

A body will travel with a constant velocity unless an external force acts on it. E.g., friction, gravity.

Question 7

Newton’s 2nd law of motion: {Definition}

Answer 7

The rate of change of movement of the body is proportional to the force applied and takes place in the direction of the force.

Question 8

Newton’s 3rd law of motion: {Definition}

Answer 8

When a body A exerts force on a body B, then body B exerts an equal but opposite force a body A.

Question 9

Force is: {Definition} & {Formula}

Answer 9

Force is that which causes acceleration. [F=ma]

Question 10

A Newton is: {Definition}

Answer 10

A Newton is: the force that causes a mass of 1kg to gain an acceleration of 1 ms-2.

Question 11

Friction is: {Definition}

Answer 11

Friction is a force that opposes motion when two objects slide over each other.

Question 12

Momentum is: {Formula}

Answer 12

Momentum is: p =mv [p: momentum, m: mass, v: velocity] kg m/s

Question 13

Principle of conservation of momentum is: {Definition}

Answer 13

Principle of conservation of momentum is: the total momentum before an interaction equals dumb after an interaction if there are no external forces acting.

Question 14

Density is: {Formula}

Answer 14

Density is: p = m/v [p: density, m: mass, v: volume] kg/m3

Question 15

Pressure is: {Formula}

Answer 15

Pressure is: P = F/A [P: pressure, F: force, A:area] Pa

Question 16

A Pascal is: {Definition}

Answer 16

A Pascal is: the pressure when a force of 1N is exerted on an area of 1 m2.

Question 17

Boyles Law is: {Definition}

Answer 17

Boyles Law is: At constant temperature for a fixed mass of gas pressure is inversely proportional to volume.

Question 18

Archimedes principle is: {Definition}

Answer 18

Archimedes principle is: when a body is partially or wholly immersed in a fluid, it experiences an apparent loss in weight (upthrust) equal in magnitude to the weight of the fluid displaced.

Question 19

Law of floatation is: {Definition}

Answer 19

Law of floatation is: the weight of floating body = weight of fluid displaced.

Question 20

Work is: {Formula}

Answer 20

Work is: W = Fs [W:Work, F:Force, s:displacement]

Question 21

A Joule is: {Definition}

Answer 21

A Joule is: the work done when a force of 1N is exerted for a distance of 1m.

Question 22

Energy is: {Definition}

Answer 22

Energy is: the ability to do work. [J]

Question 23

Kinetic energy is: {Formula}

Answer 23

Kinetic energy is: Ek = 1/2 mv2 [E: energy, m: mass, v: velocity] [J]

Question 24

Potential energy is: {Formula}

Answer 24

Potential energy is: Ep = mgh [E: energy, m: mass, g:acceleration due to gravity, h: height] [J]

Question 25

Principle of conservation of energy is: {Definition}

Answer 25

Principle of conservation of energy is: energy cannot be created or destroyed, it can only be changed from one form into another.

Question 26

Power is: {Formula}

Answer 26

Power is: P = w/t [P: power, w: work, t: time]

Question 27

A Watt is: {Definition}

Answer 27

A Watt is: the power when 1 Joule of work is done in 1 second

Question 28

Percentage Efficiency is: {Formula}

Answer 28

Percentage Efficiency is: (Power output/Power input) x 100 [%]