IB Mechanics B - Energy and Momentum

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1. Which of these expressions is the rate of change of momentum?
  • A. Δp
  • B. m/t
  • C. Δm/t
  • D. Δp/Δt
2. One of Newtons laws of motion states that the rate of change of momentum is equal to
  • A. Acceleration
  • B. Force
  • C. Mass
  • D. velocity
3. A firework rocket accelerates for the first few seconds and gains height above the ground. Which of the following best describes the energy changes taking place at this point?
  • A. chemical and potential converted to kinetic
  • B. kinetic converted to chemical and potential
  • C. chemical converted to potential and kinetic
  • D. potential converted to kinetic and chemical

4. The graph shows the force required to stretch a steel cable.

What work has been done stretching the cable by 12 cm?

  • A. 240 J
  • B. 120 J
  • C. 2.4 J
  • D. 1.2 J
5. Momentum is defined as ..
  • A. the product of mass and velocity
  • B. the force required to stop an 1kg object travelling at 1ms-1
  • C. the speed of an object multiplied by its mass in kg
  • D. the rate of change of force

6. A small steel ball of mass m is fired at a solid wall at a speed v. It rebounds at a speed of v/2.

The total momentum change is

  • A. 3mv/2
  • B. mv/2
  • C. 2mv
  • D. 2mv/3
7. An inelastic collision is one in which..
  • A. the final velocity is less than the impact velocity
  • B. momentum is not conserved
  • C. kinetic energy is not conserved
  • D. the final average velocity is less than the initial average velocity
8. A 20g bullet hits a 40g stationary block of wood at 60ms-1 and remains embedded in the wood. What is the final velocity of block and bullet?
  • A. 40 ms-1
  • B. 30 ms-1
  • C. 25 ms-1
  • D. 20 ms-1