Past Papers Physics

# Past Papers Physics :customs: [General](https://hackmd.io/PSmcWR3WT_SNDZnpQnEXDw) :arrow_left: [Physics IB](https://hackmd.io/SghtJEg3SqKPilIHHKQWng) ## Index 1. **2022 November Examination Session** 2. **Exam 2** ## 2022 November :::spoiler **Paper 1** ### Paper 1 [Original Paper](https://a.ibdocs.org/IB%20PAST%20PAPERS%20-%20SUBJECT/Group%204%20-%20Sciences/Physics_HL/2022%20November%20Examination%20Session/Physics_paper_1__HL.pdf) [Solutions](https://a.ibdocs.org/IB%20PAST%20PAPERS%20-%20SUBJECT/Group%204%20-%20Sciences/Physics_HL/2022%20November%20Examination%20Session/Physics_paper_1__HL_markscheme.pdf) 1. **What is the definition of the SI unit for a force?** A. The force required to accelerate, in the direction of the force, a mass of 1kg at 1ms^-2^ B. . The force required to accelerate, in the direction of the force, a mass at 1ms^-2^ C. The weight of a mass of 0.1kg D. The change in momentum per second :::spoiler **Solution** :::success $F = ma$ Therefore solution is: A. The force required to accelerate, in the direction of the force, a mass of 1kg at 1ms^-2^ ::: 2. **A rectangular sheet of paper has dimensions of (30.0 ± 0.5) cm and (20.0 ± 0.5) cm. What is the percentage uncertainty of the perimeter of the paper?** A. 1% B. 2% C. 2.5% D. 4% :::spoiler **Solution** :::success $\Delta y = \Delta a ± \Delta b$ $perimeter = 30.0 + 30.0 + 20.0 + 20.0 = 100.0cm$ $\Delta y = 0.5 + 0.5 + 0.5 + 0.5 = ±2.0cm$ $P$~uncertainty~ = $\Delta y / perimeter * 100 = 2%$ Therefore solution is: B. 2% ::: 3. Two forces, F and G, act on a system. ![image](https://hackmd.io/_uploads/SJBDdmcN6.png) ![image](https://hackmd.io/_uploads/SJQXY7c4T.png) :::spoiler **Solution** :::success D. ![image](https://hackmd.io/_uploads/BJMo5mc4p.png) ::: 4. Ball 1 is dropped from rest from an initial height *h*. At the same instant, ball 2 is launched vertically upwards at an initial velocity *u*. ![image](https://hackmd.io/_uploads/rytxi79Na.png) At what time are both balls at the same distance above the ground? A. $h \over 4u$ B. $h \over 2u$ C. $h \over u$ D. $2h \over u$ :::spoiler **Solution** :::success Using the formula $X$~f~ = $X$~o~ $+ vt +$ $1 \over 2$$at$^2^ For Ball 1: $X$~f~ $= h + 5t$^2^ For Ball 2: X = $ut + 5t$^2^ Substitute and solve: $h + 5t$^2^ = $ut + 5t$^2^ $t =$ $h \over u$ Therefore the solution is: C. $h \over u$ ::: 5. The diagram shows the trajectory of a projectile and the velocity v of the projectile at point P in its trajectory. P is located before the projectile reaches the peak altitude. Air resistance acts on the projectile. The acceleration of the projectile at P is a ![image](https://hackmd.io/_uploads/BkQL_EqVp.png) What are the magnitudes of the horizontal component and the vertical component of the acceleration of the projectile at P? ![image](https://hackmd.io/_uploads/HkYFd4q4a.png) :::spoiler **Solution** :::success P is located before the projectile reaches the peak altitude. Horizontal component of *a* must go over the air resistance, therefore non-zero. Vertical component of *a* must go over gravity, therefore greater than 9.8ms^-2^. B. non-zero, greater than 9.8 ms^-2^ ::: 6. An object of mass 2.0kg is on a horizontal surface. The object is pulled by a force of 12.0N and accelerates at 2.0ms^-2^. What is the coefficient of dynamic friction between the object and the surface? ![image](https://hackmd.io/_uploads/S1UGh49Ep.png) A. 0.3 B. 0.4 C. 0.6 D. 0.8 :::spoiler **Solution** :::success Formulas: $F = ma$, $F$~Friction~ $= \mu N$ $F = 2 \times 2 = 4N$ $F$~Friction~ $=12 - 4 = 8N$ $8 = 20 \times \mu$ $\mu = 0.8$ Solution: D. 0.8 ::: 7. A person lifts a total mass of 20kg through a vertical distance of 0.60m. The person repeats the lift *n* times to transfer a total energy of 6.0 × 10^4^ J. What is *n*? A. 5 B. 50 C. 500 D. 5000 :::spoiler **Solution** :::success $W = F(\cos \theta) d$ $W = 200 \times 0.06 = 120 J$ $n = 60000 / 120 = 500$ C. 500 ::: 8. An engine is exerting a horizontal force *F* on an object that is moving along a horizontal surface at a constant velocity *v*. The mass of the object is *m* and the coefficient of dynamic friction between the object and the surface is µ. What is the power of the engine? A. $Fv \over \mu$ B. $\mu Fv$ C. $mgv \over \mu$ D. $\mu mgv$ :::spoiler **Solution** :::success $P = W/t$ $P = Fd/t$ $P = \mu mgv$ D. $\mu mgv$ ::: 9. A model rocket is launched from rest. The graph shows the variation with time *t* of the net force *F* applied on the rocket. The average mass of the rocket is 0.20kg. ![image](https://hackmd.io/_uploads/Hy5XFh5Vp.png) What is the maximum velocity reached by the rocket? A. 3.0ms^-1^ B. 25ms^-1^ C. 75ms^-1^ D. 150ms^-1^ :::spoiler **Solution** :::success $F =$ $\Delta p \over \Delta t$ $J = F\Delta t$ $J = \Delta p$ $p = mv$ $\Delta p = 20.0 \times 0.50$ $1 \over 2$ $+ 1 \times 10 = 15Ns$ $v =$ $15\over 0.20$ $= 75ms$^-1^ C. 75ms^-1^ ::: 10. Three samples of the same liquid are mixed in an insulated container. The masses and initial temperatures of the samples are: ![image](https://hackmd.io/_uploads/B1m2gciNp.png) What is the equilibrium temperature of the mixture? A. 45°C B. 36°C C. 30°C D. 24°C :::spoiler **Solution** :::success $T =$ $(2 \times 60 + 2 \times 30 + 0 \times 1)\over 5$ $= 36°C$ B. 36°C ::: ::: ## Exam 2 1. **A stone falls from rest to the bottom of a water well of depth *d*. The time *t* taken to fall is 3.0 ± 0.3s. The depth of the well is calculated to be 30m using** *d=$1 \over 2$ at^2^* **. The uncertainty in a is negligible. What is the absolute uncertainty in d?** A. ±0.6m B. ±3m C. ±24m D. ±6m :::spoiler **Solution** :::success $d =$$1\over 2$$at$^2^ $\Delta y \over y$ $=|n$$\Delta a \over a$$|$ $\Delta y = 30 \times |2$$0.3\over 3.0$$|= ±6m$ D. ±6m ::: 2. **On a clear day, in the absence of air resistance, a cannon ball is fired at an angle $\theta$ to the ground with an initial velocity *u*. It's horizontal range is *s*. Which of the following statements is incorrect?** A. The time of flight is $s\over u \cos \theta$ B. The time of flight is $2u \sin \theta \over g$ where *g* is the acceleration of free fall. C. The shadow of the cannon ball moves with a constant velocity while the ball is in flight. D. The linear momentum of the cannon ball is constant during flight. :::spoiler **Solution** :::success The momentum of the cannon ball is not linear, therefore solution is: D. The linear momentum of the cannon ball is constant during flight. ::: 3. **Which row gives the correct Newton's third law force pair for a book on a table?** | | Force A | Force B | | -------- | -------- | -------- | | A. |Weight of the book|Force of the book on the table| | B. |Gravitational force of the Earth pulling on the book|Gravitational force of the book pulling on the Earth| | C. |Weight of the book|Reaction force from the table surface| | D. |Gravitational force of the Earth pulling on the book|Gravitational force of the table pulling on the Earth| :::spoiler **Solution** :::success B. Force A -- Gravitational force of the Earth pulling on the book. Force B -- Gravitational force of the book pulling on the Earth ::: 4. **A pendulum bob is suspended by a thread. The bob is moved to the right and released so that the pendulum oscillates isochronously. Taking motion to the left to be positive, which of the following statements is incorrect about the motion of the pendulum?** A. The potential energy of the system will reach its maximum value three times in one oscillation. B. At $T\over 4$ the kinetic energy of the system is at its maximum value and the velocity is maximum in the positive direction. C. At $3T\over 4$ the kinetic energy of the system is at its maximum and the velocity is at a maximum in the negative direction. D. At $T\over 2$, the force is acting in the negative direction and the kinetic energy is at its maximum value. :::spoiler **Solution** :::success D. At $T\over 2$, the force is acting in the negative direction and the kinetic energy is at its maximum value. ::: 5. **A pendulum bob on a string oscillates in SHM with a frequency, *f*.** **The period, *T*, of a simple pendulum is related to the length of the string, *l*, and the acceleration of free fall, g, by the following equation:** $T=2\pi$$\sqrt{\dfrac{l}{g}}$ **What is the ratio of the new frequency to the original frequency if the length of the string is increased by a factor of 4?** A. $1 \over \sqrt 2$ B. $1\over 2$ C. $\sqrt 2$ D. 4 :::spoiler **Solution** :::success B. $1\over 2$ ::: 6. **A body moves in a circle with increasing angular velocity. At times *t*, the angles $\theta$ swept out by the body added cumulatively from the same reference point and its angular velocities $\omega$ are as follows:** | t / s | $\theta$ / rad | $\omega$ / rad s^-1^ | | -------- | -------- | -------- | | 5 | 2 | 0.4 | | 15 | 16 | 2.4 | | 25 | 42 | 4.4 | | 35 | 80 | 6.4 | **The angular acceleration of the body:** A. is constant at 0.2 rad s^-2^ B. gradually decreases and is 6.25 rad s^-2^ when t = 15s C. is constant at 0.4 rad s^-2^ D. increases at a constant rate and is 0.2 rad s^-2^ when t = 15s :::spoiler **Solution** :::success A. is constant at 0.2 rad s^-2^ ::: 7. **Skipped** 8. **A rectangular object sits at rest on a ** :::spoiler **Solution** :::success D. :::