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Physics Grade 12 Unit 2: Two-dimensional motion

48 national exam questions have come from this unit. It runs 45 pages; one careful study pass takes about 5.3 hours, and its difficulty is moderate among Physics units. Each section below lists the questions set from it, with the year, and opens the page that teaches it.

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2.1 Projectile motion · read p. 25

2018 E.C., Q43 – A horizontal distance jumper athlete jumps from the ground with initial speed v at an angle θ with the horizontal. For the constant initial speed, the range R is related to the maximum height h
2017 E.C., Q42 – A projectile is thrown from a level ground with an initial velocity $\vec{v}_0$ making an angle of $\theta$ above the horizontal. If the maximum height covered by the projectile is $H$, then what is the horizontal range
2017 E.C., Q43 – Assume that a ball is thrown horizontally from a building of height $h$ above the ground with initial speed $v_0$. Which one of the following statements is correct about the motion of the object?
2015 E.C., Q46 – A bullet is fired with an initial speed v at an angle θ with the horizontal. It takes a time T to reach its maximum vertical displacement hmax. It hits the target point a distance R away and exactly in the horizontal lev
2013 E.C., Q29 – A bullet of 200 g mass fired from a 30.0 m high building, horizontally. At the same time a bullet of the same mass fired vertically down from the same height. What can be concluded about the motion of the two bullets?
2012 E.C., Q39 – A boy throws a ball vertically upward with an initial speed of 20 m/s. Neglecting air resistance, which of the following is true about the motion of the?
2011 E.C., Q8 – A shell is fired from a gun, whose barrel is inclined at an angle to the horizontal. During the flight, the shell explodes in air into fragments. The center of mass of different fragments will follow
2010 E.C., Q5 – A bullet is fired at an angel of 30° above the horizontal. If air resistance is neglected, what should be the bullet's ( ) a x ( ) a y horizontal acceleration and vertical acceleration when it reaches its maximum height?
2009 E.C., Q1 – The range of cannon-ball fired horizontally from a laboratory table is equal to 8/3 times the height of the table. What is the direction of velocity vector of the projectile as it strikes the ground?
2007 E.C., Q7 – If a long distance jumper athlete leaves the ground at an angle of above the horizontal surface at a speed of 10.0m/s, how far does he jump in the horizontal direction?
2006 E.C., Q27 – A placekicker must kick a football from a point which is at a distance of 36.0 m from the goal. When kicked, the 37∘ ball leaves the ground with a speed of 20.0m/s at an angle of to the horizontal. If the ball hits the c
2006 E.C., Q11 – Two projectiles are fired from ground level at equal speed but different angles. One is fired at an angle of 30 degrees and the other at 60 degrees. The projectile to hit the ground first will be the one fired at (neglec

2.2 Rotational Motion · read p. 39

2018 E.C., Q34 – A uniform disk of radius 10.0 cm is rotating at an angular velocity of 20.0 rad/s about an axis through its center. What is the centripetal acceleration of a point at a distance of 6.0 cm from the axis?
2017 E.C., Q28 – A wheel of radius, $r = 50\text{cm}$, rotates about a fixed perpendicular axis that passes through its center. If the angular speed is $\omega = 200\frac{\text{rad}}{\text{s}}$, how much is the tangential speed of a poin
2016 E.C., Q13 – Two points P 1 and P 2 on a rigid body are located at different distances, d 1 and d 2 respectively, from the pivot point O as shown in the figure below. If a body is set to rotate about the pivot point O,
2013 E.C., Q50 – A wheel starts rotating at 1.2 Hz and reaches 1.8 Hz in 5 seconds. Calculate the angular displacement it covers within 5 seconds?
2012 E.C., Q30 – A disk of radius 0.10m and mass 0.1Kg is set into motion by a tangential force of 2.0 N applied at the edge of the 400 rad/s2 disk. If the angular acceleration of the disk is , the torque and angular velocity at 2.0 s ar
2012 E.C., Q13 – At , an object undergoing SHM has maximum displacement of 0.650 m and angular frequency of 7.40 rad/s. Which of the following is correct about the motion of the oscillator?
2012 E.C., Q29 – For a rigid body rotating about a fixed axis,
2009 E.C., Q10 – A pulley is rotating at a frequency of 20rev/min. a motor speeds up the wheel so that 30s later the frequency of the motion is 60rev/min. How far a point on the pool 0.30m from its center will has travelled during that p
2009 E.C., Q9 – A disk of radius R with uniform distribution of mass M rotates about an axis perpendicular to its plane at the rim ω 2 with angular speed the moment of inertia of the disc about the axis through the center is1/2MR . What

2.3 Rotational Dynamics · read p. 50

2018 E.C., Q41 – A force F acts on an object of mass m and produces an angular displacement Δθ, and angular acceleration α in a time interval Δt. If the moment of inertia of the object about the axis of rotation is I, the magnitude of to
2017 E.C., Q41 – Four point masses , , and are attached to a massless rod which y lays on the x-axis as shown in the figure below. How much is the moment of inertia of the system about the - axis? Question Diagram kg\cdotpm2 kg\cdotpm2
2016 E.C., Q5 – An electric motor exerts a constant 10 N⋅m torque on a grindstone, which has a moment of inertia of 5.0 kg⋅m 2 about its axis. The system starts from rest and turns. What is the work done by the motor in 4.0 s?
2015 E.C., Q14 – A 30 kg rigid object has a moment of inertia 45 kg⋅m 2 about its center of mass. What is the object's moment of inertia when it rotates through an axis 2 m away and parallel to the axis through its center of mass?
2014 E.C., Q18 – A torque τ rotates an object of mass m and moment of inertia I through an angle θ. The work done on the object by the torque is
2013 E.C., Q32 – Which one of the following statement is correct about, a bar on which a force acts at one end and pivoted at the other?
2013 E.C., Q51 – If you are given the following physical quantities in angular motion: torque (?), Linear momentum (?), moment of inertia (I), angular speed (?), and angular acceleration (?). The angular momentum (L) is the
2011 E.C., Q15 – Five beads of equal mass are fixed on a rigid light rod that is free to rotate about a frictionless vertical bearing. The arrangement is such that, four of them are placed at 0.25 m and the fifth one is at 0.5m from the
2011 E.C., Q16 – A thin circular ring of mass M and radius r and moment of inertia is rotating about its axis with a constant ω angular velocity . Two objects each of mass m, are attached gently to the opposite ends of a diameter of the
2011 E.C., Q17 – In a playing room a turn table of radius 2m has moment of inertia and is rotating about a frictionless vertical axel. When a boy of mass 50Kg stands near the rim, the system rotates with angular speed 3rad/s. The boy wal
2010 E.C., Q13 – If in a given rotational system of a body the angular momentum is increased with time, which one of the following statement is not correct?
2008 E.C., Q17 – The rotational analogue of mass is
2008 E.C., Q5 – Determine the torque in Nm due to a force F =(2i ᓼ 3j + 4k)N acting at point r=(3i + 2j + 3k)m about the origin?
2008 E.C., Q18 – If the impulse of a rotating disc is non zero what can you conclude?
2007 E.C., Q15 – A double-headed vertical arrow at the left of the figure spans the height of the rectangle and is labelled 6 m, with the annotation "Hyp=?" written alongside it. A double-headed horizontal arrow along the bottom of the r

2.4 Planetary motion and Kepler’s laws · read p. 54

2018 E.C., Q25 – Our planet Earth has an orbital period of 365 days and its mean distance from the Sun is Re = 1.495 × 108 km. If there is another unknown planet whose mean distance from the Sun is R = 4Re, how much is an orbital period
2016 E.C., Q45 – Consider two satellites A and B with mass m A and m B respectively, and orbiting the earth at height h A and h B above the earth's surface. Which one of the following statements correctly describes the motion of these sa
2014 E.C., Q19 – A satellite revolves around the earth in a circular orbit of radius r = 4 x 1016 m. The period of the satellite is

2.5 Newton’s law of universal Gravitation · read p. 59

2017 E.C., Q29 – Suppose your mass is measured to be 50 kg. If your friend having a mass of 55 kg is at a distance 2 m apart from you, what is the magnitude of gravitational force between you and your friend?
2015 E.C., Q4 – What is the acceleration due to gravity at an altitude twice the radius of the Earth? ($g_E$ is the gravitational acceleration on the surface of the Earth).
2014 E.C., Q8 – Which of the following is true about satellite motion?
2012 E.C., Q16 – Which one of the following is correct statements about the intensity of sound?
2012 E.C., Q41 – According to Newton's law of Universal Gravitation,
2005 E.C., Q29 – The planet Jupiter is about 318 times as massive as earth, yet on its surface you would weigh only about 2.4 times your weight on earth. Why is this happened?