9-1 Topic 2 Forces

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At which of these times is the resultant force on Joe bigger than the resultant force on Sam?

  • 15 s
  • 11 s
  • 7 s
  • 3 s

Some students investigate a model of the craters produced by meteorite impacts. They drop balls into a tray filled with sand. They use six balls with different masses. They drop each ball from the same height. Which one of these graphs shows the relationship between the gravitational potential energy (gpe) of the balls and their mass when they are all at the same height?

  • D
  • C
  • B
  • A

Sam and Joe are on their bikes. They are on a flat, straight road. Joe is stationary when Sam rides past at a constant velocity of 10 m/s. Joe waits for 4 s and then follows Sam. This is a velocity/time graph of their motion. How far did Sam travel during these 15 s? (distance = velocity time)

  • 150 m
  • 100 m
  • 10 m
  • 1.5 m

Complete the sentence

  • not moving
  • moving at a constant speed
  • decelerating
  • accelerating

The diagram shows the forces acting on a car which is travelling along a flat straight road. The size of the resultant force on the car is 350 N. In which direction is the resultant force acting?

  • up
  • to the right
  • to the left
  • down

Which of these situations can increase the reaction time of a driver?

  • driving for a long time without taking a break
  • stopping for a cup of coffee
  • worn tyres on his car
  • an icy road