No questions found
In this experiment, you will investigate the upthrust on an object partly immersed in water.
(a) Measure and record the height $H$ of the flask, as shown in Fig. 1.1.
$$H = \text{...............................} \text{cm} \; [1]$$
(b) Assemble the apparatus as shown in Fig. 1.2, with the bottom of the flask approximately 4 cm below the water surface.
(c) (i) Measure and record the height $h_w$ of the water surface above the bench, as shown in Fig. 1.2.
$$h_w = \text{........................................} \text{cm}$$
(ii) Measure and record the height $h_b$ of the bottom of the flask above the bench, as shown in Fig. 1.2.
$$h_b = \text{............................................} \text{cm}$$
(iii) Record the newton-meter reading $F$.
$$F = \text{...............................................} \text{N} \; [1]$$
(iv) Calculate $x$, using $x = h_w - h_b$.
$$x = \text{.............................................} \text{cm} \; [1]$$
(d) Adjust the height of the boss and repeat (c) until you have six sets of values of $h_w$, $h_b$ and $F$.
For all values of $h_b$, the water surface should be in contact with the \textit{sloping} sides of the flask.
Include values of $x$ and $(H - x)^3$ in your table.
$$[9]$$
(e) (i) Plot a graph of $F$ on the $y$-axis against $(H - x)^3$ on the $x$-axis.
$$[3]$$
(ii) Draw the straight line of best fit.
$$[1]$$
(iii) Determine the gradient and $y$-intercept of this line.
$$\text{gradient} = \text{..........................................}$$
$$y\text{-intercept} = \text{......................................}$$
$$[2]$$
(f) The quantities $F$, $H$ and $x$ are related by the equation
$$F = a(H - x)^3 + b$$
where $a$ and $b$ are constants.
Using your answers in (e)(iii), determine the values of $a$ and $b$.
Give appropriate units.
$$a = \text{..............................................}$$
$$b = \text{..............................................}$$
$$[2]$$
559
551
556
In this experiment, you will investigate the motion of a flywheel rolling down a ramp.
(a) You are provided with a small flywheel, as shown in Fig. 2.1.
(i) Measure and record the diameter $d$ of the axle.
\(d = \text{.................................................... cm} [1]\)
(ii) Measure and record the diameter $D$ of the flywheel.
\(D = \text{.................................................... cm} [1]\)
(b) You have also been provided with a track. Set up the track with one end raised above the bench, as shown in Fig. 2.2.
The height $h$ should be approximately 8 cm.
(i) Measure and record the length $l$ of the track.
\(l = \text{..................................................}\)
(ii) Measure and record the height $h$ above the bench of the raised end of the track.
\(h = \text{..................................................}\)
(iii) Measure and record the distance $s$ between the two marks on the track.
\(s = \text{..................................................} [1]\)
(c) (i) Place the axle of the flywheel on the track at the upper mark as shown in Fig. 2.3. Release the flywheel and watch it roll down to the lower mark (the top of the flywheel may need a gentle push to start it rolling).
(ii) Replace the axle of the flywheel on the track at the upper mark. Take measurements to find the time $t$ taken for the flywheel to roll from the upper mark to the lower mark.
\(t = \text{..................................................} [2]\)
(iii) Estimate the percentage uncertainty in your value of $t$.
\(\text{percentage uncertainty} = \text{..................................................} [1]\)
(iv) Theory suggests that an approximate value for the acceleration of free fall $g$ is given by:
$$g = \frac{s l D^2}{h d t^2}.$$
Calculate a value for $g$. Give an appropriate unit.
\(g = \text{..................................................} [1]\)
(d) (i) Push the two plastic tubes onto the axle to increase the diameter of the axle, as shown in Fig. 2.4.
(ii) Repeat (a)(i) and (c)(ii).
\(d = \text{.................................................. cm}\)
\(t = \text{..................................................} [2]\)
(e) It is suggested that the relationship between $t$ and $d$ is
\(t = \frac{k}{d}\)
where $k$ is a constant.
(i) Using your data, calculate two values of $k$.
\(\text{first value of } k = \text{..................................................}\)
\(\text{second value of } k = \text{..................................................} [1]\)
(ii) Justify the number of significant figures you have given for your values of $k$.
........................................................................................................................
........................................................................................................................
........................................................................................................................ [1]
(iii) Explain whether your results in (e)(i) support the suggested relationship.
........................................................................................................................
........................................................................................................................
........................................................................................................................ [1]
(f) (i) Describe four sources of uncertainty or limitations of the procedure for this experiment.
1. ........................................................................................................................
........................................................................................................................
2. ........................................................................................................................
........................................................................................................................
3. ........................................................................................................................
........................................................................................................................
4. ........................................................................................................................
........................................................................................................................ [4]
(ii) Describe four improvements that could be made to this experiment. You may suggest the use of other apparatus or different procedures.
1. ........................................................................................................................
........................................................................................................................
2. ........................................................................................................................
........................................................................................................................
3. ........................................................................................................................
........................................................................................................................
4. ........................................................................................................................
........................................................................................................................ [4]
596
531
501
