Year 11 Physics Kinematics Sheet 1

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A tutorial sheet of harder questions on kinematics is given below.

  1. A car travels back and forth between two towns. The speed during the forward journey is v1. If the speed during the return journey is v2, what is the average speed for the entire trip?[2v1v2/(v1+v2)]
  2. A car travels back and forth between two towns. The average speed during the forward journey is 50km/h. What is the speed for the return journey if the average speed for the entire trip was 40 km/h?
  3. An object moves from rest with constant acceleration for 4.0 s then with uniform velocity for 5.0s, the total distance travelled being 224 m. What was the acceleration?
  4. Two airports, A and B, are 850 km apart with B due east of A. At 10 am a jet takes off from A and travels at a constant velocity of 400 km/h to the east. At 11 am an aircraft takes off from B and travels at a constant velocity of 500 km/h to west. At what time do they pass each other?
  5. Two camels leave the Sphinx at times 52.5 s apart. The first moves off with a uniform acceleration of 1.30 ms-2 which it maintains for 1.92 s. It then continues with the acquired speed. The second camel moves off with a uniform acceleration of 1.45 ms-2 which it maintains for 2.84 s. It then continues with the acquired speed. Calculate the time taken by the second camel to overtake the first camel and the distance travelled in this time.[82.9 s, 336 m]
  6. A moving trolley is observed to have the following positions at equal intervals of 1 second; 5.10, 1.60, 1.50, 4.80, 11.5 and 21.6 cm. Show that the acceleration is uniform and determine its magnitude. What is the next number in the list? [3.40 cms-2, 35.1 cm]
  7. An elevator can increase its speed with an acceleration a and slow down with a deceleration b. What is the least time that it can travel a distance d if it starts and finishes at rest?
  8. A stone is dropped down a well. The sound of the splash is heard after a time interval t. What is the depth of the well if the speed of sound is vs? Give the answer in terms of g, t and vs.

HSC Physics Transformers

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Most HSC students can apply the transformer equation, but often the Physics principles are misunderstood. A tutorial sheet on transformers is given below.

  1. What is the role of a transformer in the transmission of electricity?
  2. Define one volt.
  3. Define the term emf.
  4. Is voltage is the same as emf?
  5. What is the role of the iron core in a transformer?
  6. What is meant by a soft iron core? Why is the soft iron core laminated?
  7. Can a transformer operate using DC? Sketch a graph showing the primary and secondary voltage (on different axes) when the DC voltage applied to the primary coil is switched on and then after a short time switched off.
  8. A common examination response is that "the induced emf in a coil equals the rate of change of the magnetic flux through the coil". Why is this incorrect?
  9. When AC enters the primary coil of a transformer in which coil is an emf induced? Primary, secondary or both?
  10. Assuming that the primary coil has low resistance, is the voltage applied to the primary coil equal to the counter emf induced in the primary coil? Is a counter emf induced in the secondary coil?
  11. Explain how an emf is induced in the secondary coil.
  12. The transformer equation uses the symbols Vp and Vs. Since transformers use AC, in which the current varies with time, what do these symbols represent?