Tag: measurement of area, volume and density

Questions Related to measurement of area, volume and density

Multiple choice physics learning how to measure measurement of area and volume measurement of volume measurement of area, volume and density

A cubic metre of water at $0^o$C is solidified into ice, density of ice is $0.96$ of water at $0^o$C. Which of the following deductions are true?
$1$. Water expands when solidified.
$2$. Ice will float in water at $0^o$C with half its volume above the surface.
$3$. Density of all liquids are higher than its density when solidified.

  1. $3$ only
  2. $2$ only
  3. $1$ only
  4. $1$ and $2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When water freezes into ice, its density decreases, meaning its volume increases (it expands). This expansion is a unique property of water. Statement 1 is true. Statement 2 is false because ice floats with about 90% of its volume submerged, not 50%. Statement 3 is false as a general rule.

Multiple choice physics measurements and units measurement of area and volume measurement of volume measurement of area, volume and density

A public park, in the form of a square, has an area of $(100 \pm 0.2 )m^2 $ .The side of park is :

  1. $ (10 \pm 0.01 ) m $
  2. $ (10 \pm 0.1 ) m $
  3. $ (10 \pm 0.02 ) m $
  4. $ (10 \pm 0.2 ) m $
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let the side length of the square park is $l$.

The area of a square is given as,

$A = {l^2}$

$100 = {l^2}$

$l = 10\;{\rm{m}}$

The error in length is given as,

$\dfrac{{\Delta A}}{A} = 2\dfrac{{\Delta l}}{l}$

$\dfrac{{0.2}}{{100}} = 2\dfrac{{\Delta l}}{{10}}$

$\Delta l = 0.01\;{\rm{m}}$

Thus, the side of the park is $\left( {10 \pm 0.01} \right)\;{\rm{m}}$.