IB SL Physics Poorly Answered Questions 2

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A sheet with SL questions that are not well answered is given below.

  1. The average speed of a hydrogen atom at -23 °C is v. Determine the average speed of a helium atom at -148 °C. (v/√8)
  2. The increase in volume ∆V of a solid when it is heated is proportional to both its volume V and change in temperature ∆T. What is the SI unit for the constant of proportionality?
  3. The energy stored in a stretched spring is E. What is the work done in doubling the extension of the spring? (3E)
  4. A simple pendulum of mass m is oscillating through an angle of 40°. What is the magnitude of the resultant force acting on the mass at the top of its swing? (mgcos20)
  5. A car starts from rest and moves in a straight line with uniform acceleration a. Draw a graph showing the distance travelled every second versus the total time taken.(straight line, gradient a, y-intercept -a/2)
  6. On another planet a ball is released from rest and falls 2.0 m in the third second of its movement. What is the gravitational field strength of this planet? (0.8 N kg-1)
  7. A stationary firework of mass M explodes into pieces of mass 3M/4 and M/4. The kinetic energy of the smaller piece is E. What is the kinetic energy of the larger piece? (E/3)
  8. A car moves at a constant speed v around a circular track. What is the magnitude of the change in velocity of the car after travelling through an angle of 60°? (v)

IB Physics Motion in a Vertical Circle

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A sheet of vertical circle problems is given below.

  1. A mass m is tied to a string of length L and hangs vertically at rest. The mass is given an initial horizontal speed u. What is the initial acceleration of the mass?
  2. A mass on a string is released from rest swings as a simple pendulum. What is the speed of the mass when its vertical drop is ∆h?
  3. A mass m is placed on the end of a light rigid rod of length r and made to move in a vertical circle at a constant speed v. Is the magnitude of the acceleration of the mass a constant value of v2/r? (no, this is the radial component of the acceleration only)
  4. In the previous question draw a free-body diagram if the radius to the mass makes an angle 𝜽 with the vertical when 𝜽 < 90°. Show that the force exerted on the mass by the rod has a component mgsin𝜽 perpendicular to the rod and a component mv2/r - mgcos𝜽 parallel to the rod.
  5. In the previous question at what angle to the vertical is the force exerted by the rod maximum? (180°)