Majority of the candidates attempted this question and had good and useful results. However, a few of the candidates disregarded the instruction to measure do thus, they could not get the desired results.
- Evaluation of was wrongly done.
Part (b) (i) was well attempted while the numerical part. (b)(ii) was poorly handled Most candidates substituted wrongly into a wrong formula.
The expected answers are:
- internal diameter D of beaker measured and recorded to at least 1d.p in cm
- Initial depth d* of water in the beaker measured and recorded in
cm to at least 1d.p in cm.
- Five values of M recorded in gm.
- Five values of d< measured and recorded to at least 1d.p in cm
and in trend
Trend As M increase di increases
- Five values of di - do correctly evaluated
- Composite table showing at least M, dt, and d Candidates are also expected to:
- plot five points on graph
- distinguish between the axes
- chose reasonable scales
- draw line of best fit
- evaluate k =4s/nD2
- State any two of the following precautions in acceptable language.
- Avoided parallax error in reading the metre rule
- Avoided splashing of water (Liquid)
- Avoided object (mass) from touching sides bottom of beaker Metre rule/scale vertically placed
Repeated readings shown on the table
(b) (i) Relative density (R.D) is defined as the ratio of mass ( or weight) of a substance to the mass (weight) of equal volume of water
OR
R D = mass (or weight) of a substance
Mass (or weight) of equal volume of water
OR
R.D = Density of substance Density of water
- R.D = Weight in air
Upthrust
RD = 2.7
2.7- 1.2
= 2.7
1.5
= 1.8