P2 Topic 3

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An object will accelerate when

  • A. The forces acting on it are balanced.
  • B. The forces acting on it are unbalanced.
  • C. Air resistance is equal to the object's weight
  • D. Its weight is equal to the reaction from the ground.

Jane compares the performance of some racing cars. She finds this information on the internet. Jane discovers that a racing car accelerates from 0 to 30 mph in 1.2 s. The speed of the car after 1.2 s from the start is about


  • A. 13 m/s
  • B. 16 m/s
  • C. 37 m/s
  • D. 67 m/s

A car is moving in a straight line. The graph shows the stopping of this car in an emergency. The resultant force on the car during the first second is


  • A. 0N
  • B. 50/2N
  • C. 50/1.5N
  • D. 50N

The acceleration of the car in the previous question whilst braking is

  • A. -0.1 m/s2
  • B. -9 m/s2
  • C. -10 m/s2
  • D. -12.5 m/s2

On these graphs, the solid line shows the graph on page 12. Which graph shows what would happen if the car suddenly hit a small patch of oil on the road, just as the driver started to brake.


  • A.
  • B.
  • C.
  • D.

The diagram shows some forces acting on a car. The resultant of these forces is


  • A. 2000 N to the right.
  • B. 3500 N to the right.
  • C. 5500 N to the right.
  • D. 7500 N to the right.

The graph shows how the speeds of four identical cars change with time. Which line is for the car with the largest kinetic energy at time t?


  • A.
  • B.
  • C.
  • D.

A car accelerates at 2 m/s2. The mass of the car is 1000 kg. The force producing this acceleration is

  • A. (2 / 1000) N
  • B. (2 + 1000) N
  • C. (1000 - 2) N
  • D. (1000 x 2) N

The diagram shows how the velocity of a falling object changes with time. At which point A, B, C or D is the resultant force on the object zero?


  • A.
  • B.
  • C.
  • D.

At which point A, B, C or D on the previous graph is the acceleration largest?

  • A.
  • B.
  • C.
  • D.

The mass of the engine is 100 000 kg and of each coach is 25 000 kg. When the train travels at constant speed, the engine still has to exert a force on coach Y. This is because


  • A. The coach has a large mass.
  • B. The steam carries away thermal energy.
  • C. There are frictional forces.
  • D. Gravity always acts at right angles to the trains movement

As the engine in the previous question travels at a constant speed, it pulls on Y with a force of 10 000 N. Coach Y pulls on the engine with a force of

  • A. Zero
  • B. 9 950 N
  • C. 10 000 N
  • D. 10 050 N

As the train sets off, the resultant force on coach Y is 10 000 N. The acceleration produced by this force is

  • A. 0.067 m/sē
  • B. 0.4 m/sē
  • C. 2.5 m/sē
  • D. 15 m/sē

The photograph shows a miniature train running on a level track. The engine driver applies the brakes on the engine. Which diagram shows the horizontal forces acting on the first coach?


  • A.
  • B.
  • C.
  • D.