1.1 PHYSICAL QUANTITIES AND MEASUREMENT TECHNIQUES

Question 1

units and their basics quantities

Answer 1

three basic quantities: length, mass and time

Question 2

SI unit of length

Answer 2

meter (m)

Question 3

the area of square or rectangle

Answer 3

area = length × breadth

Question 4

what is volume and its SI unit

Answer 4

volume is the amount of space occupied. unit of volume is cubicmetre (m power 3)

Question 5

measuring volume of a liquid and regular solid

Answer 5

Liquid - the volume of a liquid may be obtained by pouring it into a measuring cylinder
Regular solid - volume of rectangular block
= length × breadth × height
volume of cylinder
= π × radius × height

Question 6

SI unit of time

Answer 6

seconds (s)

Question 7

describe how to measure a variety of time intervals using clocks and digital timers

Answer 7

To measure an interval of time in an experiment,
first choose a timer that is precise enough for the
task. A stopwatch that records times with a precision of 1s or 0.1s is suitable for finding the period in seconds of a pendulum. To measure very short time intervals, a digital clock that can be triggered to start and stop by an electronic signal from a microphone.
Accuracy can be improved by measuring
longer time intervals.

Question 8

scalars and vectors

Answer 8

A scalar quantity has magnitude only
A vector quantity has magnitude and
direction

Question 9

Scalar quantities

Answer 9

distance
speed
time
mass
energy
temperature

Question 10

vector quantities

Answer 10

displacement
force
weight
velocity
acceleration
momentum
electric field strength
gravitational field strength