Basics Of Physics

Question 1

What SI Units?

Answer 1

Fundamental Units (Base) Of physical quantities

Question 2

What is the SI unit of mass?

Answer 2

Kg (kilogram)

Question 3

What physical quantitiy is measured in mol?

Answer 3

Amunt of substance

Question 4

What is the SI unit of current?

Answer 4

A (amperes)

Question 5

What is the SI unit for Temperature?

Answer 5

K (Kelvin)

Question 6

What is the SI unit for length?

Answer 6

m (meters)

Question 7

What quantity is measured in seconds?

Answer 7

Time

Question 8

Are Newtons (N) an SI unit?

Answer 8

No Newtons are not fundemental the SI Units for Newtons is Kgms-² (Because force = mass x acceleration)

Question 9

Derrive the SI units for acceleration?

Answer 9

Kinetic energy = ½ x mass x velocity^2
Units = Kg x m/s x m/s
Kg m^2 s^-2

Question 10

Derrive The SI unit of force?

Answer 10

Force = mass x acceleration
Units = kg x m/s^-2
kg ms^-2

Question 11

Express 60TΩ in standard form

Answer 11

6 x 10^13

Question 12

Write 0.000003m with a suitable prefix

Answer 12

3µm

Question 13

What is the actual value of 8MΩ?

Answer 13

8,000,000Ω

Question 14

What is 6000pF in nF?

Answer 14

6nF as 1 nano is a 1000 pico

Question 15

What multiplier is asociated with the prefix kilo?

Answer 15

x1000 (10^3)

Question 16

What multiplier is asociated with the prefix femto?

Answer 16

10^-15

Question 17

Express 75GΩ in standard form

Answer 17

7 x 10^9 Ω

Question 18

What is 1 eV in J?

Answer 18

1eV is 1.6 x 10^-19J

Question 19

Express 6kWh in J?

Answer 19

6kW = 6000 J/s 1 hour = 3600s

6kWh = 6000 x 3600

= 21.6 x 10^6 J
= 21.6MJ

Question 20

Convert 6.6 pJ to eV

Answer 20

6.6pJ = 6.6 x 10^-12 J

divide by 1.6 x 10^-19

6.6 pJ = 4.1 x 10^7 eV
= 41MeV

Question 21

What is meant by a scalar quantity?

Answer 21

A quantity that only has a magnitude

Question 22

What is a vector quantity?

Answer 22

A quantity that has a direction aswell as a magnitude

Question 23

Is acceleration vector or scalar?

Answer 23

Vector

Question 24

Is mass vector or scalar?

Answer 24

Scalar

Question 25

what equation is used to calculate density?

Answer 25

Density = mass / volume

Question 26

What is a moment?

Answer 26

A turning force
force x perpendicular distance from the of the line of action of the force

Question 27

If an object is in equilibrium the sum of its anticlockwise movements would be

Answer 27

Equal to the some of the clockwis =e movement (principle of movements)

Question 28

If an object is in equilibrium it means the object is

Answer 28

Not accelerating.It is either:
Stationary
moving at a constant velocity

Question 29

How can the forces on a object be shown to be in equilibrium?

Answer 29

Adding the horizontal and vertical components of the forces acting on it and showing they equal zero
or if there are three forces acting on an object you can draw a scale diagram - if the scale diagram forms a closed triangle ,then the object is in equilibrium.

Question 30

What is meant by a couple?

Answer 30

A pair of equal and opposite coplanar forces that have equal magnitude and opposite direction applied to a body parallel to eachother but not along the same line.

Question 31

What is meant by centre of gravity?

Answer 31

The point through which all weight of an object acts.For a uniform object the centre of gravity is the geometric centre of the object.