Question

The man bought a mirror of area 0.3m² whose width is 40cm,the find the length of the mirror.

Answer 1

Answer:

V±ΔV=(2.7±0.14)m

3

Here, m±Δm=(12.4±0.1) kg

and, p±Δp=(4.6±0.2)kg/m

3

Volume, v=

p

m

=

4.6

12.4

=2.69m

3

=2.7m

3

(rounding off to one decimal place )

Now,

V

ΔV

=±(

m

Δm

+

p

Δp

)

ΔV=±(

m

Δm

+

p

Δp

)×V

=±(

12.4

0.1

+

p

0.2

)×2.7=±0.14

∴V±ΔV=(2.7±0.14)m

3

Answer 2

Answer:

75cm

Explanation:

area of mirror = width x length

0.3m² = 40cm x length

0.3x10000cm²r 40cm x length

3000cm2 = 40cm x length

length = 3000/40cm = 75cm.