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<h2>SL Paper 3</h2><div class="specification">
<p><span style="background-color: #ffffff;">A uniform ladder of weight 50.0 N and length 4.00 m is placed against a frictionless wall making an angle of 60.0° with the ground.</span></p>
<p><span style="background-color: #ffffff;"><img src="data:image/png;base64,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"></span></p>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p><span style="background-color:#ffffff;">Outline why the normal force acting on the ladder at the point of contact with the wall is equal to the frictional force <em>F</em> between the ladder and the ground.</span></p>
<div class="marks">[1]</div>
<div class="question_part_label">a.</div>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p><span style="background-color:#ffffff;">Calculate <em>F.</em></span></p>
<div class="marks">[2]</div>
<div class="question_part_label">b.</div>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p><span style="background-color:#ffffff;">The coefficient of friction between the ladder and the ground is 0.400. Determine whether the ladder will slip.</span></p>
<div class="marks">[2]</div>
<div class="question_part_label">c.</div>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question" style="padding-left: 20px;">
<p style="text-align:left;"><span style="background-color:#ffffff;">«translational equilibrium demands that the» </span><span style="background-color:#ffffff;">resultant force in the horizontal direction must be zero✔<br></span></p>
<p style="text-align:left;"><span style="background-color:#ffffff;">«hence <em>N</em><sub>W</sub> = <em>F»</em></span></p>
<p style="text-align:left;"><span style="background-color:#ffffff;"><em><span style="background-color:#ffffff;">Equality of forces is given, look for reason why.</span></em></span></p>
<div class="question_part_label">a.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p style="text-align:left;"><span style="background-color:#ffffff;">«clockwise moments = anticlockwise moments»<br></span></p>
<p style="text-align:left;"><span style="background-color:#ffffff;">50 × 2cos 60 = <em>N</em><sub>W</sub> × 4sin 60 ✔</span></p>
<p style="text-align:left;"><span style="background-color:#ffffff;"><span style="background-color:#ffffff;">«<span class="mjpage"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{N_{\text{W}}} = F = \frac{{50 \times 2\cos 60}}{{4\sin 60}}">
<mrow>
<msub>
<mi>N</mi>
<mrow>
<mtext>W</mtext>
</mrow>
</msub>
</mrow>
<mo>=</mo>
<mi>F</mi>
<mo>=</mo>
<mfrac>
<mrow>
<mn>50</mn>
<mo>×</mo>
<mn>2</mn>
<mi>cos</mi>
<mo></mo>
<mn>60</mn>
</mrow>
<mrow>
<mn>4</mn>
<mi>sin</mi>
<mo></mo>
<mn>60</mn>
</mrow>
</mfrac>
</math></span>»</span></span></p>
<p style="text-align:left;"><span style="background-color:#ffffff;"><em>F</em> = <span style="background-color:#ffffff;">14.4«<em>N</em>» ✔</span></span></p>
<div class="question_part_label">b.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p style="text-align:left;"><span style="background-color:#ffffff;">maximum friction force = «<span style="display:inline !important;float:none;background-color:#ffffff;color:#000000;font-family:Verdana , Arial , Helvetica , sans-serif;font-size:14px;font-style:normal;font-variant:normal;font-weight:400;letter-spacing:normal;text-align:left;text-decoration:none;text-indent:0px;white-space:normal;">0.4 × 50N</span>» = 20«N» ✔<br></span></p>
<p style="text-align:left;"><span style="background-color:#ffffff;">14.4 <span style="display:inline !important;float:none;background-color:#ffffff;color:#000000;font-family:Verdana , Arial , Helvetica , sans-serif;font-size:14px;font-style:normal;font-variant:normal;font-weight:400;letter-spacing:normal;text-align:left;text-decoration:none;text-indent:0px;white-space:normal;"><</span> 20 <em><strong>AND</strong> </em>so will not slip ✔</span></p>
<div class="question_part_label">c.</div>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question" style="padding-left: 20px;">
<p>Many candidates stated that the resultant of all forces must be zero but failed to mention the fact that horizontal forces must balance in this particular question.</p>
<div class="question_part_label">a.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p>Very few candidates could take moments about any point and correct answers were rare both at SL and HL.</p>
<div class="question_part_label">b.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p>The question about the slipping of the ladder was poorly answered. The fact that the normal reaction on the floor was 50N was not known to many.</p>
<div class="question_part_label">c.</div>
</div>
<br><hr><br><div class="specification">
<p>A wheel of mass 0.25 kg consists of a cylinder mounted on a central shaft. The shaft has a radius of 1.2 cm and the cylinder has a radius of 4.0 cm. The shaft rests on two rails with the cylinder able to spin freely between the rails.</p>
<p style="text-align: center;"><img src="images/Schermafbeelding_2018-08-12_om_16.44.54.png" alt="M18/4/PHYSI/SP3/ENG/TZ2/06"></p>
</div>
<div class="specification">
<p>The stationary wheel is released from rest and rolls down a slope with the shaft rolling on the rails without slipping from point A to point B.</p>
<p style="text-align: center;"><img src="images/Schermafbeelding_2018-08-12_om_16.47.09.png" alt="M18/4/PHYSI/SP3/ENG/TZ2/06.a"></p>
</div>
<div class="specification">
<p>The wheel leaves the rails at point B and travels along the flat track to point C. For a short time the wheel slips and a frictional force <em>F </em>exists on the edge of the wheel as shown.</p>
<p style="text-align: center;"><img src="images/Schermafbeelding_2018-08-12_om_16.49.45.png" alt="M18/4/PHYSI/SP3/ENG/TZ2/06.b"></p>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p>The moment of inertia of the wheel is 1.3 × 10<sup>–4</sup> kg m<sup>2</sup>. Outline what is meant by the moment of inertia.</p>
<div class="marks">[1]</div>
<div class="question_part_label">a.i.</div>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p>In moving from point A to point B, the centre of mass of the wheel falls through a vertical distance of 0.36 m. Show that the translational speed of the wheel is about 1 m s<sup>–1</sup> after its displacement.</p>
<div class="marks">[3]</div>
<div class="question_part_label">a.ii.</div>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p>Determine the angular velocity of the wheel at B.</p>
<div class="marks">[1]</div>
<div class="question_part_label">a.iii.</div>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p>Describe the effect of <em>F </em>on the linear speed of the wheel.</p>
<div class="marks">[2]</div>
<div class="question_part_label">b.i.</div>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p>Describe the effect of <em>F </em>on the angular speed of the wheel.</p>
<div class="marks">[2]</div>
<div class="question_part_label">b.ii.</div>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question" style="padding-left: 20px;">
<p>an object’s resistance to change in rotational motion</p>
<p><strong><em>OR</em></strong></p>
<p>equivalent of mass in rotational equations</p>
<p> </p>
<p><em>OWTTE</em></p>
<p><strong><em>[1 mark]</em></strong></p>
<div class="question_part_label">a.i.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p>ΔKE + Δrotational KE = ΔGPE</p>
<p><strong><em>OR</em></strong></p>
<p><span class="mjpage"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="\frac{1}{2}">
<mfrac>
<mn>1</mn>
<mn>2</mn>
</mfrac>
</math></span><em>mv</em><sup>2</sup> + <span class="mjpage"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="\frac{1}{2}">
<mfrac>
<mn>1</mn>
<mn>2</mn>
</mfrac>
</math></span><em>I</em><span class="mjpage"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="\frac{{{v^2}}}{{{r^2}}}">
<mfrac>
<mrow>
<mrow>
<msup>
<mi>v</mi>
<mn>2</mn>
</msup>
</mrow>
</mrow>
<mrow>
<mrow>
<msup>
<mi>r</mi>
<mn>2</mn>
</msup>
</mrow>
</mrow>
</mfrac>
</math></span> = <em>mgh</em></p>
<p> </p>
<p><span class="mjpage"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="\frac{1}{2}">
<mfrac>
<mn>1</mn>
<mn>2</mn>
</mfrac>
</math></span> × 0.250 × <em>v</em><sup>2</sup> + <span class="mjpage"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="\frac{1}{2}">
<mfrac>
<mn>1</mn>
<mn>2</mn>
</mfrac>
</math></span> × 1.3 × 10<sup>–4</sup> × <span class="mjpage"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="\frac{{{v^2}}}{{1.44 \times {{10}^{ - 4}}}}">
<mfrac>
<mrow>
<mrow>
<msup>
<mi>v</mi>
<mn>2</mn>
</msup>
</mrow>
</mrow>
<mrow>
<mn>1.44</mn>
<mo>×</mo>
<mrow>
<msup>
<mrow>
<mn>10</mn>
</mrow>
<mrow>
<mo>−</mo>
<mn>4</mn>
</mrow>
</msup>
</mrow>
</mrow>
</mfrac>
</math></span> = 0.250 × 9.81 × 0.36</p>
<p><em>v</em> = 1.2 <strong>«</strong>m s<sup>–1</sup><strong>»</strong></p>
<p> </p>
<p><em><strong>[3 marks]</strong></em></p>
<div class="question_part_label">a.ii.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p><em>ω</em> <strong>«</strong>= <span class="mjpage"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="\frac{{1.2}}{{0.012}}">
<mfrac>
<mrow>
<mn>1.2</mn>
</mrow>
<mrow>
<mn>0.012</mn>
</mrow>
</mfrac>
</math></span><strong>»</strong> = 100 <strong>«</strong>rad s<sup>–1</sup><strong>»</strong></p>
<p><strong><em>[1 mark]</em><br></strong></p>
<div class="question_part_label">a.iii.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p>force in direction of motion</p>
<p>so linear speed increases</p>
<p><em><strong>[2 marks]</strong></em></p>
<div class="question_part_label">b.i.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p>force gives rise to anticlockwise/opposing torque on</p>
<p>wheel ✓ so angular speed decreases ✓</p>
<p> </p>
<p><em>OWTTE</em></p>
<p><strong><em>[2 marks]</em></strong></p>
<div class="question_part_label">b.ii.</div>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question" style="padding-left: 20px;">
[N/A]
<div class="question_part_label">a.i.</div>
</div>
<div class="question" style="padding-left: 20px;">
[N/A]
<div class="question_part_label">a.ii.</div>
</div>
<div class="question" style="padding-left: 20px;">
[N/A]
<div class="question_part_label">a.iii.</div>
</div>
<div class="question" style="padding-left: 20px;">
[N/A]
<div class="question_part_label">b.i.</div>
</div>
<div class="question" style="padding-left: 20px;">
[N/A]
<div class="question_part_label">b.ii.</div>
</div>
<br><hr><br>